PROSODY IN DINÉ BIZAAD NARRATIVES: A QUANTITATIVE INVESTIGATION OF ACOUSTIC CORRELATES 1
KAYLA PALAKURTHY
UNIVERSITY OF CALIFORNIA, SANTA BARBARA
This article is an empirical examination of prosodic correlates used to demarcate dis- course units in a collection of Diné bizaad narratives. This study builds on observations of prosodic patterns in related Dene languages and evaluates the presence of hypothesized correlates of following pause, syllable lengthening, pitch lowering, and pitch reset at boundaries for intonation units and syntactic sentences. Based on an analysis of nine narratives, I fnd that the Diné narrator marks the majority of her intonation units with a following pause, as well as with signifcant rhyme lengthening in the fnal syllable and a slight, but signifcant pitch reset at the beginning of the unit. The results further show that the narrator marks syntactic sentences with longer following pauses and pitch lowering on unit-fnal syllables along with a unit-initial pitch reset. Together, these results present em- pirical evidence for prosodic marking of discourse units in Diné bizaad connected speech. [KEYWORDS: Diné bizaad, Navajo, Dene languages, prosody, intonation]
1. Introduction. The presence of meaningful intonation is considered to be a universal feature of speech (Hockett 1966; Gordon 2016); speak- ers of all languages use intonation, as well as other prosodic features, to express afect, to indicate information structure, and to demarcate syntactic or discourse-level units (Himmelmann and Ladd 2008). In line with these cross-linguistic tendencies, studies of languages within the Dene (Athabas- kan) family have identifed prosodic correlates for discourse units within personal narratives (Berez 2011; Lovick and Tuttle 2012). In previous stud- ies of discourse in Diné bizaad or Navajo (ISO code: nav), a Dene language spoken in the present-day American Southwest, scholars have similarly re- counted auditory impressions of meaningful prosodic and intonational pat- terns. Specifcally, they describe sentence-fnal pitch falls (Landar 1963; Mithun 2008), the strategic use of pause to create rhetorical momentum (Mithun 2008), and the intentional lengthening of syllables for emphasis
1 I am very grateful to Marianne Mithun for providing these recordings and transcripts, and to Dolly Soulé for sharing these stories. This paper benefted from insightful comments on ear- lier drafts from Marianne Mithun, Matthew Gordon, and Stefan Gries, as well as from the very helpful anonymous reviewers and editors at IJAL. I received additional helpful feedback from conference audiences at SSILA 2017 and ASA 2016. Any remaining errors are my own. This research has been supported by an NSF GRFP Fellowship (2014178334).
[IJAL, vol. 85, no. 4, October 2019, pp. 497–531] © 2019 by The University of Chicago. All rights reserved. 0020–7071/2019/8504–0001$10.00 DOI 10.1086/7004564 497 498 international journal of american linguistics
(Kiser 2014). Yet an instrumental study of Diné bizaad sentences fnds no evidence that speakers prosodically mark sentence boundaries in elicited materials (McDonough 2003a). Given these earlier observations and fol- lowing Berez (2011) and Lovick and Tuttle (2012), the goals of the pres- ent study are to empirically substantiate whether acoustic measurements of pauses, pitch measurements, and syllable length statistically correlate with posited discourse unit boundaries in a set of nine Diné bizaad personal nar- ratives. The forthcoming analysis will show that the narrator, Ms. Soulé, consistently demarcates intonation units with unit-fnal syllable lengthening, pauses, and a slight but signifcant unit-initial pitch reset. At the same time, Ms. Soulé has longer pauses and lower pitch at the ends of her syntactic sentences, as well as a pitch reset in sentence-initial position. The rest of this paper proceeds as follows: in 2, I provide background on Diné bizaad. In 3, I present an overview of cross-linguistic research on prosody and intonation with a focus on results from earlier studies of Dene prosody. 4 includes a description of the nine analyzed narratives, the methods applied to identify the relevant discourse units, and the quantitative methods used to evaluate the presence of pauses of diferent lengths, unit-fnal lengthening, unit-fnal pitch lowering, and unit-initial pitch reset. 5 presents the results for each investigated correlate with evidence for prosodically marked intonation units and syntactic sentences. In 6, I discuss the implications of this research given previous work on Diné bizaad prosody.
2. Background on Diné Bizaad. Diné bizaad is a Southern Dene language spoken predominantly in and around the Navajo Nation in the North American Southwest (ISO 639–3, nav). Though there are more than 150,000 Diné bizaad speakers (Siebens and Julian 2011), the language is threatened by rapid and ongoing intergenerational shift to English (House 2002; Spolsky 2002). The Diné bizaad consonant inventory has 32 phonemes and closely re- sembles that of other Dene languages (McDonough 2003b). The Diné bizaad vowel inventory has four vowels: /i e o a/ with phonemic distinctions for na- sality, tone, and length (Young and Morgan 1987; McDonough 2003b) as well as three diphthongs /ei ai oi/ (Young and Morgan 1987:xii). 2 Table 1 presents the phonemic consonant inventory adapted from McDonough (2003b:6) and Iskarous et al. (2012:197). The Diné language is tonal with a phonological tone target, high or low, for every syllable (McDonough 1999). Falling and rising tonal contours are restricted to long vowels and vowel clusters (Young and Morgan 1987;
2 Nasal vowels are marked in the Diné bizaad orthography with a nasal hook, high-tone vowels are marked with an acute accent, long vowels are written VV, and short vowels, V. Glottal stops are indicated with an apostrophe <’>. prosody in diné bizaad narratives 499
TABLE 1 DINÉ CONSONANTS IN IPA
Labial Coronal Lateral Palatal Velar Labialized velar Glottal Obstruents unaspirated p t ts tl tʃkɡw ʔ aspirated th tsh tɬh tʃh kh khw ejective t’ ts’ tɬ’ tʃ’ k’ Fricatives voiceless s ɬʃx h voiced z ʒ ɣ Approximants w l j Nasals m n
McDonough 1999; Zhang 2002). The default low tone is said to be more widespread than the high tone, and though tone is lexically contrastive, there are few genuine minimal pairs; tonal contrasts are largely restricted to stems (McDonough 1999). (1) shows a tone minimal pair with contrasting tone on the long vowel. This and all following examples will be written in the Diné bizaad orthography. (1) ’azéé’ ‘mouth, throat, neck’ ’azee’ ‘medicine, drug, herb’ (Young and Morgan 1987:143) Syllables in Diné bizaad typically align with morpheme boundaries (Court- ney and Saville-Troike 2002). In the stem domain, the Diné bizaad syllable structure is CV(V)(C) (McDonough 2003b), while prefxal syllables tend to have a CV syllable structure (McDonough 2003b). Prefxes containing the nasal consonant /n/ followed by a vowel may be realized as a syllabic [n̩ ] with the nasal retaining the tone of the absorbed vowel (Reichard 1951; McDonough 2003b). In terms of morphological structure, Diné bizaad is a polysynthetic language with individual verbs often constituting entire clauses. Full noun phrases are rare in Diné bizaad narratives, and diferent pronominal prefxes are avail- able for speakers to simultaneously track multiple participants within a story (McCreedy 1983). The Diné bizaad verb is prefxing with up to nine pre- fx positions according to the most widespread version of the verb template (Young and Morgan 1987), and verbs must minimally comprise a verb-fnal stem preceded by a classifer and subject/mode prefxes (McDonough 2003b). Enclitics may attach to the verb stem. Verbs tend to occur clause-fnally fol- lowing an SOV order (Young and Morgan 1987).
3. Prosody and intonation. The study of prosody, taken here to refer to patterns of suprasegmental features related to pitch, rhythm, and pauses in spoken language, has been broached by scholars refecting a range of 500 international journal of american linguistics distinct theoretical paradigms. In particular, research on prosody in natu- rally produced spoken discourse has emphasized the relevance of intonation units, streams of speech that occur “under a single prosodic contour” (Chafe 1979, 1987, 1994). Researchers have proposed that intonation units serve cognitive functions in discourse; speakers use intonation units to modulate the amount of new information given at a single moment (Chafe 1994), and experimental tasks show that intonation units facilitate processing due to a connection between the form of an intonation unit and cognitive work- ing memory constraints (Simpson 2016). Other studies fnd that intonation units often align with syntactic clausal or phrasal units (Chafe 1994; Croft 1995) and serve as a frequent site of bilingual code-switches (Shenk 2006). Intonation units have been identifed in many languages, and despite the name, perceptible correlates of intonation unit boundaries consist of more than intonation, defned as “the occurrence of recurring pitch patterns, each of which is used with a set of relatively consistent meanings, either on single words or on groups of words” (Cruttenden 1997:7). Other frequently discussed prosodic correlates for intonation units include following pause, boundary tones, pitch reset, fnal-syllable lengthening, and the manipulation of unit- initial speech rate (Du Bois et al. 1993). Intonation units have been identifed in discourse from Dene languages: Ahtna (Berez 2011), Dena’ina (Lovick and Tuttle 2012), and Diné bizaad (Kiser 2014). 3 In the forthcoming analysis, I likewise assume that intonation units can be perceptually identifed in the narrative recordings. The discourse-centered research on intonation units (summarized above) remains quite distinct from the substantial literature that has investigated prosody from the perspective of intonational phonology, including the Autosegmental-Metrical model (Ladd 1996), a frequently applied analytical approach. Within this research tradition, studies have focused on cross-lin- guistic investigations of diferent domains of phonological constituents within the framework of a prosodic hierarchy (Beckman and Pierrehumbert 1986; Nespor and Vogel 1986; Jun 2005). Despite applying a diferent theoretical and methodological framework from the aforementioned discourse studies, many phonological studies of the prosodic hierarchy describe an intonational phrase, a unit that resembles the aforementioned intonation unit. Like intona- tion units, intonational phrases are thought to be the domain of intonation contours, and “the ends of intonational phrases coincide with positions in which pauses may be introduced” (Nespor and Vogel 2007:188). The com- position of intonational phrases can vary widely, depending on speech style and breath placement, but often correspond to simple syntactic sentences and parenthetical asides. Similar to intonation units, intonational phrases are
3 Lovick and Tuttle (2012) state that their “intonation unit” is probably comparable to Crut- tenden’s (1997) “intonation group.” prosody in diné bizaad narratives 501 believed to serve a cognitive function; they are considered “optimal chunks for linguistic processing” (Nespor and Vogel 2007:194). Beyond the intonation unit, discourse-based studies present evidence for a larger discourse unit with prosodically delineated boundaries. Similar units have been variously identifed as prosodic sentences (Chafe 1994; Genetti and Slater 2004; Applebaum 2013) and story units (Lovick and Tuttle 2012). Though these units remain less well-defned prosodically than intonation units, studies report a recurring pattern whereby some intonation units cluster to- gether to form larger units (Himmelmann 2006). These units are described as being perceptibly distinct from intonation units (Wennerstrom 2001). Prosodic sentences may co-occur with amplifed realizations of the same correlates used to mark intonation units: Lovick and Tuttle (2012) document both intonation units and story units marked with fnal pauses, but pauses after the larger story units are longer. A study on the Nepali language, Dolakhā Newar, describes prosodic grouping of intonation units whereby fnal units display boundary tones or syllable lengthening, and prosodic fnality is found to mirror syntactic fnality (Genetti and Slater 2004). Intonational phonology studies similarly describe a higher domain of prosodic patterning labeled the “phonological utterance,” which in some syntactic and semantic circumstances may “consist of one or more intonational phrases” (Nespor and Vogel 2007:221). In terms of their internal composition, prosodic sentences have been defned as having “one center of interest” (Chafe 1994:142), and Lovick and Tuttle describe their story units as “the closest oral discourse correlate to the concept of a sentence” (2012:303). Syntactically, prosodic sentences may co-occur with fnite verbs to reinforce the notion of fnality within a narrative sentence (Genetti and Slater 2004) or may correspond to topic shifts in discourse or junctures of narrative episodes (Wennerstrom 2001). I hypothesize that, in addition to using prosody to mark intonation unit boundaries, the narrator of these stories will also demarcate the boundaries of prosodic sentences in the narrative discourse. Previous studies have identifed prosodic correlates that mark similar units in both tonal and nontonal Dene languages. 4 Despite variation within the fam- ily, together the extant literature points to syllable lengthening and boundary tones, especially a pervasive sentence-fnal pitch fall, as prosodic correlates to discourse units. For instance, Berez (2011) conducted a quantitative in- vestigation of prosodic correlates for intonation units in Ahtna, a nontonal Northern Dene language spoken in Alaska, and found that syllable pacing, in the form of fnal lag, and pitch reset are strong perceptual cues for intona- tion units. In Dena’ina, another nontonal Northern Dene language spoken in Alaska, Lovick and Tuttle (2012) report prosodic evidence for intonation
4 See Rice and Hargus (2005) for a more comprehensive overview of prosody in the Dene family. 502 international journal of american linguistics units and the larger story unit based on a quantitative analysis of prosodic correlates in discourse. In their recordings, speakers marked intonation units with pauses and fnal rhyme lengthening while longer pauses and fnal pitch lowering delineate story units, which often align with syntactic sentences. Likewise, other studies describe prosody in tonal Dene languages. Based on a phonetic description of Jicarilla Apache, a Southern Dene language spoken in New Mexico, speakers exhibit sentence-fnal syllable lengthen- ing of both consonants and vowels without notable unit-internal intonation (Tuttle and Sandoval 2002). An Autosegmental-Metrical study of prosody in the Northern Alberta dialect of Danezaa (Beaver), a Northern Dene language, reports a low boundary tone in declaratives and questions (Schwiertz 2009). Speakers also make use of a rising boundary tone marking uncertainty and a low falling tone that co-occurs with a particular question particle (Schwiertz 2009). In a detailed study applying the framework of intonational phonology supplemented with acoustic measurements, Holton (2005) analyzes the inter- action between tone and intonation in Tanacross, a Northern Dene language spoken in Alaska. Holton identifes four sentence-fnal intonation contours: a declarative fnal fall and interrogative fnal high-rise, which preserve the pitch contrast between high and low tones, and two additional melodies that do not (Holton 2005:268). Finally, Dene grammars of San Carlos Apache, a Southern Dene language, and Slave, a Northern Dene language, each contain insights into intonation patterns of the respective languages. For instance, the grammar of San Carlos Apache mentions that long and short high-tone syllables at the ends of sentences will be realized with high pitch followed by a subsequent fall (de Reuse 2006:58). This sentence-fnal pitch fall is associated with both declaratives and questions. Likewise, the grammar on Slave notes falling intonation in declarative sentences, while polar questions can be formed with a particle plus sentence-fnal falling intonation or without a morphological marker and with rising intonation and vowel lengthening, especially of high-tone vowels (Rice 1989). Furthermore, distinct intonation contours are described for conjoined sentences and complex clauses, and stem vowels are often lengthened for emphasis (Rice 1989:49). As for Diné bizaad, several studies have analyzed word-level prosody in the language. Diné bizaad is reported to have no defned word-level stress as verifed by instrumental phonetic research (McDonough 1999), though speakers realize a wider pitch range and longer segments in stem morphemes (McDonough et al. 1993; McDonough 1999, 2003b). Further, only in the stem does the full consonant inventory appear (McDonough 2003a), and intervo- calic consonants are reported to double in stem-initial position (Young and Morgan 1987; Bird 2004). Stress is typically found on stem morphemes in other Dene languages, and the reported phonotactic patterns that render Diné bizaad stems prominent resemble correlates of stress (Rice and Hargus 2005). prosody in diné bizaad narratives 503
Landar (1959), in a descriptive work, characterizes Diné bizaad stress that is primarily realized as “loudness.” According to Landar, stress is not restricted to stems but may be mobilized to emphasize particles, verb prefxes, or stems (Landar 1959). An in-depth discussion of word-level stress is beyond the scope of this paper, but “word” is included in the statistical models below to serve as a point of comparison for efects at larger discourse boundaries. Other descriptions of prosody in Diné bizaad provide somewhat conficting results with regard to intonation, and no quantitative studies have investigated prosodic correlates of units larger than the word. A lack of intonation in the language is impressionistically noted by Swadesh (1934), a sentiment echoed in reported intuitions of Diné bizaad–speaking linguists (McDonough 2003a). However, other scholars describe pauses and fnal falls marking syntactic sentences in connected speech. In auditory descriptions included in his dis- sertation on syntax, Landar (1963) repeatedly refers to terminal contours, indicated in his work with an arrow pointing down, and defnes a unit, which he calls a macrosegment, as an “utterance bound initially by pause or a terminal contour and fnally by a terminal contour. . . . Most macrosegments end with falling terminal contour and are coterminous with clauses” (Landar 1963:12). Mithun (2008) makes a similar observation: syntactic sentences in personal narratives are marked by a full fall in pitch. Mithun (2008) also notes that pauses are used strategically in personal narratives; as the story progresses, the tempo of speech increases. Of particular relevance to the present topic is an earlier analysis of the form and function of Diné bizaad intonation units examined in diferent genres of discourse available on YouTube (Kiser 2014). Kiser transcribed these re- cordings into intonation units using the methods outlined in Du Bois et al. (1993) and cites the use of audible pauses, tempo, lengthening, and falling pitch to segment the units. Kiser (2014) found that 56% of intonation units align with syntactic main clauses, and overall 97% of the intonation units are grammatically complete units. With regard to prosodic phrasing at intonation boundaries, she notes boundary tones classifed as continuing or fnal (after Du Bois et al. 1993). However, although Du Bois et al. (1993) mention that the diference between continuing and fnal boundary tones is a functional dis- tinction and that the phonetic realization of these tones will vary by language, Kiser does not describe the pitch patterns of these boundary tones in Diné bizaad. In her examples, although not all clauses end with fnal intonation, all fnal contours occur at the ends of clauses. She also briefy mentions the presence of intonation chaining, though she not does not specify the details of how it is realized in the recordings. Lastly, she reports that all speakers use syllable lengthening “for stylistic purposes,” such as emphasizing forth- coming information or holding the foor while searching for a word (Kiser 2014:128). This work points to the presence of Diné bizaad intonation units, 504 international journal of american linguistics typically a grammatical unit, bounded by pauses, and signaled by audible pitch movements. Adding to these auditory descriptions of Diné bizaad intonation, in an Au- tosegmental-Metrical study, McDonough (2003a) instrumentally investigates sentence-level boundary tones in elicited examples and fnds no evidence for consistent pitch movements marking the ends of questions, focus construc- tions, or statements. McDonough (2003a) further suggests that this lack of intonation is expected given the syntax of Diné bizaad as a pronominal argu- ment language with an SOV word order. This restriction does not extend to other Dene languages that have diferent argument structures (McDonough 2003a). Instead of intonation, it is proposed that Diné bizaad speakers use morphological particles to convey similar afective, epistemic, and supraseg- mental meanings oft-conveyed by intonation in other languages (Young and Morgan 1987; McDonough 2003a). This overview of Diné bizaad prosody reveals some discrepancies in the previously reported results. In a carefully controlled phonetic study, speakers display no meaningful intonation patterns in elicited materials, whereas in descriptive studies of spontaneous speech, scholars observe pitch falls corre- sponding to the end of declarative sentences, a pattern found in descriptions of syntactic and prosodic sentences in several other Dene languages. Given this background, in the present study, I seek to add to the instrumental literature on prosody in Diné bizaad by examining acoustic measurements of pitch and other prosodic correlates at unit boundaries in connected speech.
4. Methods. The data for this study come from nine narratives re- corded by Professor Marianne Mithun in 2001 with Ms. Dolly Hermes Soulé, a bilingual Diné bizaad–English speaker. At the time of recording, Ms. Soulé was 65 years old and living in California, though she grew up in the Navajo Nation town of Chinle, Arizona. The recordings were made using a solid-state digital recorder at a sampling rate of 44,100 Hz. Shortly after recording the narratives, Professor Mithun and Ms. Soulé transcribed the audio into intonation units and provided glosses and translations. Table 2 provides information about each narrative, including the number of syllables and pauses analyzed in this study. The descriptive titles in table 2 were given at the time of the recording and refect the topic of each narrative. The narratives are all personal stories with the exception of the Pear Story. 5 4.1. Annotation. In order to examine phonetic evidence for prosodic correlates of discourse units, I frst segmented the narrative discourse into syllables, words, intonation units, and syntactic sentences. I then conducted
5 The Pear Story is the retelling of a flm used for cross-linguistic discourse elicitation (Chafe 1980). prosody in diné bizaad narratives 505
TABLE 2 ANNOTATED NARRATIVES
Narrative Length Syllables Pauses Sheepskin 3:05 453 63 Rain 3:06 389 56 Powwow 1:31 234 32 Boarding School 2:52 387 46 Cibecue Camp 0:20 55 8 Corner 0:32 108 8 Mountain Lion 1:45 275 31 Jehovah’s Witnesses 1:45 257 37 Pear Story 4:07 683 90 Total 19:03 2,841 374 a quantitative analysis of the acoustic phonetic evidence for each of four well-attested prosodic correlates: pauses, fnal rhyme lengthening, fnal pitch lowering, and pitch reset, with the prediction being that based on the qualitative observations above, Ms. Soulé uses these prosodic correlates to demarcate intonation units and syntactic sentences. More precisely, I hypothesize that pauses are more frequent after these units than elsewhere in the narrative, that the fnal syllables of intonation units and syntactic sentences are signifcantly diferent from syllables in other positions with regard to rhyme lengthening and F0 measurements, and that unit-initial syllables coincide with a pitch reset. By employing mixed-efects regression modeling, I aim to identify patterns at unit boundaries, while also account- ing for confounds that might otherwise obscure such efects. 4.1.1. Intonation units. When segmenting intonation units, I followed the methods of discourse transcription described in Du Bois et al. (1993) and applied in Berez (2011) and Lovick and Tuttle (2012). I identifed intonation units in the narratives by listening for chunks of speech produced under one prosodic contour typically bounded by pauses (Chafe 1979, 1987), but some- times also cued by syllable pacing and coherent internal tune. This method relies on auditory perception; waveforms and spectrograms were not examined at this stage. A comparison between the present intonation unit segmentation and that originally done in 2001 yields 96% alignment. As stated in 3, intonation units in many languages tend to be smaller than sentences and often align with clausal or phrasal units. In these recordings, 49% of intonation unit boundaries align with clause boundaries. This compares with 60% overlap in English (Chafe 1994), 46% in Dena’ina (Lovick and Tuttle 2012), and 56% in Kiser’s (2014) study of Diné bizaad. 6 Example (2)
6 A possible explanation for the diference between Kiser’s results and those shown here is that Kiser’s data come from online videos, many of which were aimed at learners of the language. 506 international journal of american linguistics
FIG. 1—Pitch track of (2) from Ms. Soulé’s Rain narrative presents an intonation unit that contains a complete syntactic sentence. The length (in milliseconds) of following pauses is written in parentheses after the cited text. This utterance is bounded by pauses and occurs with a perceptible intonation contour. 7 (2) ’Ákǫ́ǫ́ diit’ash dii’nóo. (170 ms) ’ákǫ́ǫ́ di–iid–’ash di–iid–ní=go over.there INCEP–1DU–DU.go.FUT oral–1DU–say.IPFV=SUB ‘We’ll go over there, we said.’ Figure 1 displays the accompanying pitch track for (2) in order to provide a visual of pitch movement within the unit. The displayed pitch ranges from 50 to 300 Hz.
In more carefully delivered speech, one might expect individual contours to align with clauses more often than in spontaneous speech. 7 The following abbreviations are used in glosses: 1, frst person; 3, third person; 3s, ‘space, area, impersonal it’; 3a, ‘he, she, they one, a person, people’; AnO, animate object; CLF, classi- fer; DEM, demonstrative; DU, dual; FUT, future; INCEP, inceptive; IPFV, imperfective; ITER, iterative; OBJ, object; PFV, perfective; PL, plural; POSS, possessive; PST, past; SBJ, subject; SG, singular; SUB, subordinate; TERM, terminative; TOPIC, topicalizer; and USIT, usitative. prosody in diné bizaad narratives 507
FIG. 2—Pitch track of (3) and (4)
Example (3), from Ms. Soulé’s Sheepskin narrative, shows an intonation unit composed solely of the discourse marker ’áádóó ‘and then’, and the in- tonation unit in (4) completes the sentence. The pitch track for this sentence is shown in fgure 2. (3) ’Áádóó (500 ms) ’áádóó ‘And then,’ (4) ’áádóó shı́ ı̨́ ̨ neeztı́ .̨ (1233 ms) ’áádóó shı́ ı̨́ ̨ n–eez–tı́ ̨ then perhaps TERM–3.PFV–AnO.PFV ‘then he must have laid down.’ Semantically, speakers of many languages tend to limit their intonation units to one piece of new information at a time (Chafe 1994), a constraint that is reportedly upheld in Diné bizaad intonation units (Kiser 2014). Similarly, in examples (5–7) from the beginning of the Mountain Lion narrative, Ms. Soulé conveys each piece of new information in a separate intonation unit. 508 international journal of american linguistics
FIG. 3—Pitch track of (5)–(7)
(5) Hádą ́ ą ́ ’léiya shighandi, (523 ms) há=dą ́ ą ́ ’=léi=ya shi–ghan=di sometime=PST=some=TOPIC 1SG.POSS–house=at ‘One day at my house,’ (6) shizhé’éyázhí shi–zhé’é–yázhí 1SG.POSS–father–little ‘my uncle,’ (7) bitah honeezgaigo. (424 ms) bi–tah ho–neez–gai=go 3.POSS–body area–3.PFV–hurt.PFV=SUB ‘was not well.’ First, she introduces the location of the story in (5), a new participant in (6), and then adds new information about the participant in (7). Example (6) is not followed by a pause but is perceptible as a unit based on cues of syllable pacing and a distinct internal intonation contour. Ms. Soulé draws out her pronunciation of shizhé’éyázhí with what sounds like an especially long vowel on the shi- prefx followed by a slow pronunciation of the rest of the word. The following intonation unit sounds much faster, and this sudden change in syllable pacing renders (6) a distinctly perceptible unit (fgure 3). As shown in these examples, intonation units vary in length and content, with many bounded by pauses. Though there is some inherent circularity to analyzing phonetic correlates that have likely played a role in the initial prosody in diné bizaad narratives 509 segmentation, the assumption here is that a convergence of prosodic features infuences the impression of a unit boundary, and subsequent quantitative analysis can identify how individual correlates correlate with the perception of these boundaries (Berez 2011). 4.1.2. Syntactic sentences. I next segmented the narratives into syntactic sentences as potential candidates for a larger prosodically marked discourse unit, similar to those described earlier as prosodic sentences. As did other scholars referenced above, although in many cases I easily identifed groups of intonation units that clustered together separated by longer pauses, I found it difcult to consistently rely solely on prosody to inform my segmentation decisions in light of the fact that I had relied on the same cues to segment intonation units. By referring to syntactic structure, I found that I could more objectively identify sentences, the boundaries of which are frequently attested sites of prosodic marking in many languages. Furthermore, given the com- parative evidence that syntactic sentences may be consistently marked with fnal pitch-lowering in Dene languages, by focusing on syntactic sentences I could more directly compare these results with those of other languages in the family. In these narratives, I segmented syntactic sentences as main clauses along with any dependent clauses, phrases, and particles. When necessary, I drew on translations provided in consultation with Ms. Soulé at the time of transcrip- tion. In these recordings, most (95.5%) syntactic sentence boundaries align with intonation unit boundaries. Syntactic sentences tend to end in a verb or with verbal enclitics and often begin with a connective or discourse marker, such as ’áádóó ‘and then’, nít’ę́ ę́ ’ ‘but then’, or ’áko ‘so’. Example (8) from the Jehovah’s Witnesses narrative shows a syntactic sentence composed of two intonation units written here on separate lines. (8) ’Asdzą ́ ą ́ dóó hastiin léi’, ’a s d zą ́ ą ́ dóó hastiin léi’ woman and man some ‘A woman and a man,’ nihaa ní’áázh. (826 ms) nih–aa ní–’áázh 1.DU–to PFV–DU.go.PFV ‘came to see us.’ The frst intonation unit is perceptible here because of its distinct tone when compared with the following intonation unit, which is also uttered at a much lower volume. A noteworthy characteristic of Diné bizaad syntactic sentences is the fre- quent use of morphologically subordinate verbs, marked with =go, as main verbs to express backgrounded discourse information (Mithun 2008). I treat 510 international journal of american linguistics subordinate clauses without a clear matrix clause as an independent syntactic sentence. For instance, in example (9) from Ms. Soulé’s Boarding School narrative, the =go morpheme occurs with the verb jiní ‘he said’. (9) ’Áko (201 ms) ’áko okay ‘“It’s okay,’ ’éí kodi naanáshdááh ’éí ko=di naaná–sh–d–ááh DEM here=at repeatedly–1SG.SBJ–CLF–one.go.ITER ‘I’ll be coming to visit you over here.”’ dooleeł jinóo. (1276 ms) dooleeł ji–ní=go future 3A.SBJ–say.IPFV=SUB ‘he said.’ The second intonation unit here is perceptible based on a distinct contour tune when compared with the third intonation unit. Again, there is a decrease in volume and some creaky phonation throughout the third intonation unit. Example (10) shows a longer sentence, also from the Boarding School narrative. (10) Ndę ́ ę ́ shı́ ı̨́ ̨ ’ákǫ ́ ǫ ́ (778 ms) nít’ę ́ é ̨’ shı́ ı̨́ ̨ ’ákǫ ́ ǫ ́ and.then perhaps here.and.there ‘But then I guess,’ ’éí ńéí (242 ms) ’éí ńléí DEM there ‘there,’ náhołdohóó ’ábidoogı́ ̨ ná–ho–ł–do=góó ’á–bi–doo–gı́ ̨ around–area–CLF–be.warm.USIT=to away–down–3.PFV–haul.PFV ‘to California we were hauled,’ hodoo’niid (1681 ms) ho–di–oo–d–niid 3s.OBJ–oral–PFV–CLF–say.PFV ‘he was told.’ This sentence is spread across four intonation units and is bounded by longer pauses than those that occur sentence-internally. The third intonation unit is prosody in diné bizaad narratives 511 not followed by a pause but is perceptible based on a distinct internal contour, a sudden drop in volume, and once again, the presence of creaky phonation in the fnal intonation unit of this sentence. 4.2. Phonetic measurements. After dividing the narratives into into- nation units and syntactic sentences, syllable rhymes, syllable nuclei, and pauses were manually segmented in Praat using time-aligned waveforms and spectrograms (Boersma and Weenink 2017). Syllables were segmented based on the aforementioned phonological descriptions of a CV(V)(C) syl- lable structure (McDonough 2003b). Syllable nuclei, which were mostly vowels, were segmented using the onset and ofset of the second formant. Syllable rhymes were segmented from the onset of the syllable nucleus until the end of the coda consonant, if present. Filler words such as uh or um were not analyzed. Following Lovick and Tuttle (2012), pauses were segmented from the end of any audible exhalations to the onset of the fol- lowing word. Pauses shorter than 100 ms were excluded, as were those that co-occur with a fller word or false start; at certain points in the story Ms. Soulé produced multiple fller words and pauses while she was preparing to recount the next part of the narrative. These junctures may systematically occur but are not relevant to the principal question of how Ms. Soulé uses prosody to mark discourse units in relatively continuous connected speech. The measurements targeted for quantitative analysis include pause distri- bution and pause length in milliseconds, syllable rhyme and syllable nuclei duration in milliseconds, and pitch measured as the fundamental frequency/ F0 in Hertz. Automated Praat scripts returned duration and F0 measurements, which were then carefully checked, and spurious measurements were manu- ally corrected. Pitch was operationalized with two F0 measurements: mean F0 with a window set to the duration of the syllable nucleus, and the F0 at a point 75% of the way through the syllable nucleus, based on fndings that Diné bizaad tonal pitch targets are realized late in the syllable (McDonough 1999). The analysis of pitch in 5.4 is based on the measurement taken from the point 75% of the way through the nucleus, while pitch reset is measured as the diference in mean F0 values between contiguous syllables. Most syllable nuclei are vowels, though the recordings include 106 syllabic nasals. I omitted pitch measurements from all syllables in English codeswitches, false starts, and fller words. Any syllable nucleus that returned an undefned mean F0, typically attributed to creaky phonation, was removed from the analysis. 8 4.3. Statistical analysis. After compiling the measurements, syllables and pauses were manually annotated for phonemic vowel length, lexical
8 Both vowel devoicing (Schwiertz 2009) and nonmodal vowel phonation (Gordon and Munro 2007) prosodically mark units in other languages, but these correlates were not investigated in these recordings. 512 international journal of american linguistics tone, morpheme type, discourse function, and the position of the syllable in the word, intonation unit (IU), and syntactic sentence with levels for each unit position designated as initial, medial, or final. Monosyllabic words and intonation units were annotated as distinct levels. Since the primary focus here is on boundary markers, the medial level contains all non-fnal or non- initial syllables within each unit, without additional internal diferentiation. 9 Because of morphologically conditioned phonological patterns in the lan- guage, morpheme type is coded with levels for stem: nominal, verbal, and postpositional; prefix: disjunct and conjunct verbal prefxes and nominal pre- fxes; and other: enclitics, adverbs, and other particles. Syllables were anno- tated for their discourse function based on the observation that quoted speech sounded much higher in pitch than the rest of the narrative. I annotated each syllable for whether it occurred as part of the main storyline, an evaluative narrator aside, or quoted speech. Table 3 summarizes the distribution of these annotated predictors. 10 The measurements of each targeted prosodic correlate then functioned as dependent variables in mixed-efects regression models with a goal of evaluat- ing the infuence of the predictors in table 3 on the realization of each correlate. The predictors are considered both individually, as main efects, and as terms that interact with other predictors in the models. The use of mixed-efects models allows for the inclusion of random efects terms such as NARRATIVE or WORD, which account for any signifcant variance between diferent nar- ratives or between individual words. The measurements were statistically analyzed in R (R Core Team 2017) with linear mixed-efects modeling using the lme4 package (Bates et al. 2015). 11 Following Zuur et al. (2009), the optimal random efects structure was identi- fed starting with a “beyond optimal model” that contains all fxed predictors and interactions. Models with diferent random efects adjustments to the slopes or intercepts were compared using Akaike information criterion values (AIC) with restricted maximum likelihood (REML). Models with the lowest AIC that were a signifcant improvement over models without random efects were selected. Random efect adjustments considered in these models include NARRATIVE, TONE, VOWEL LENGTH, and MORPHEME.
9 In eleven examples, Ms. Soulé used an English word in the initial position of an intona- tion unit. These English tokens were omitted, resulting in a slight mismatch between initial and fnal intonation unit syllables. Similarly, there were four English words with Diné enclitics leading to a similar mismatch between initial and fnal syllables in the word. For instance, the token doorjį’ ‘to the door’. 10 Other categories that were explored but proved irrelevant for statistical analysis include noun phrase position, frst mention of a nominal referent, and dependent verbs. 11 Other packages used in the analysis and visualization of these models include MuMIn (Bartoń 2016), efects (Fox 2003), car (Fox and Hong 2009), ggplot2 (Wickham 2009), and lmerTest (Kuznetsova et al. 2017). prosody in diné bizaad narratives 513
TABLE 3 DISTRIBUTION OF ANNOTATED PREDICTORS
Predictor Levels Number of Syllables VOWEL LENGTH Short 1451 Long 1086 Diphthong 198 Syllabic Nasal 106 LEXICAL TONE High 1312 Low 1406 Falling 123 MORPHEME Prefx 752 Stem 666 Other 1423 POSITION IN WORD Monosyllabic 398 Initial 905 Medial 631 Final 907 POSITION IN IU Monosyllabic 24 Initial 576 Medial 1654 Final 587 POSITION IN SENTENCE Initial 211 Medial 2419 Final 211 DISCOURSE FUNCTION Aside 197 Main Story 2446 Quoted Speech 198 WORD Individual lexical items 511 NARRATIVE Each story 9
Once the optimal random efects structure was identifed, the fxed-efects structure was determined starting from a maximal model with individual pre- dictors, listed in table 3, and relevant pairwise interactions using maximum likelihood estimation. Based on my hypotheses, I used a priori contrasts to target the statistical diferences between correlates in fnal versus non-fnal positions, and then in initial versus medial positions (Gries 2013). The process of ftting the model proceeded through a backwards model selection process, whereby individual nonsignifcant interactions and predictors were removed individually with signifcance determined by p-values. After nonsignifcant interactions or predictors were removed, the fnal models were computed again using REML. This method was similarly applied to ft each of the models for the prosodic correlates, except for pauses, which were analyzed by statistically comparing diferences in distributions. Particular adjustments for each model will be discussed alongside the results in 5. 514 international journal of american linguistics
TABLE 4 DISTRIBUTION OF PAUSE BY SYLLABLE POSITION IN IU
Initial Medial Final Monosyllabic Tokens followed by pause 0 (0%) 0 (0%) 354 (61%) 17 (71%) Total 576 1654 579 24
TABLE 5 DISTRIBUTION OF PAUSE BY SYLLABLE POSITION IN SYNTACTIC SENTENCE
Initial Medial Final Tokens followed by pause 3 (1%) 204 (8%) 164 (81%) Total 211 2419 203
5. Results. In this section I present the results of the analyses of each correlate at diferent syllabic positions within intonation units and syntac- tic sentences. The data include 2,841 syllables, 1,305 words, 611 intona- tion units, 211 syntactic sentences, and 371 pauses. In 5.1 I begin with an analysis of following pause. 5.1. Pause. The distribution of pauses by syllabic position in the into- nation unit and syntactic sentence are shown in tables 4 and 5. 12 In these narratives, the majority of intonation units (61%) were marked by a fol- lowing pause, and pauses do not occur within intonation units. Likewise, most syntactic sentences were marked with a following pause (81%), and though 204 medial syllables occur with a following pause, most medial syllables (92%) do not. Figure 4 presents boxplots comparing pause duration after syllables in each unit position. The plot for pauses following intonation units includes pauses after monosyllabic, as well as multisyllabic intonation units. Since no pauses occur within intonation units, all pauses after intonation units are also pauses after words, and thus the plots are the same. The sentence-medial tokens shown in fgure 4 include the IU-fnal tokens that are not also sentence- fnal. The duration of pauses in these narratives varies widely, as refected in the vertical height of these boxes and length of the extending whiskers. The mean duration of pauses after words and intonation units is 844 ms (SD = 494), whereas in syntactic sentences the mean duration after initial syllables is 281 ms (SD = 73), after medial syllables it is 715 ms (SD = 471), and after fnal syllables it is 1014 ms (SD = 469).
12 The totals for each unit are slightly lower here than in table 3 because I removed the 8 fnal units in each narrative where a fnal pause was indistinguishable from the end of the story. In one case, Ms. Soulé continues on beyond what is transcribed, and thus a pause can be measured. prosody in diné bizaad narratives 515
FIG. 4—Comparison of duration of following pause by syllabic position
Figure 4 shows that the observed duration of pauses after syntactic sentence- fnal syllables is longer than pauses after intonation units, a fnding confrmed to be statistically signifcant based on a nonparametric Wilcox test (W = 23762, p < 0.001). In syntactic sentences, pauses after fnal syllables are also signif- cantly longer than pauses after medial syllables (W = 23176, p < 0.001), and pauses after initial syllables (W = 458, p < 0.05). The results reveal that Ms. Soulé uses pauses to mark intonation unit and syntactic sentence boundaries, and that pauses are signifcantly longer after sentences. Next, I turn to the correlate of syllable lengthening. 5.2. Syllable lengthening. As mentioned earlier, fnal syllable length- ening has been documented as a correlate of intonation units in other Dene languages. In order to capture the efects of consonant, as well as vowel lengthening, I follow Lovick and Tuttle (2012) in analyzing the duration of syllable rhymes, in addition to syllable nuclei, in diferent positions in intonation units and syntactic sentences. As a baseline for comparison, the mean duration of Ms. Soulé’s vowels are shown in table 6 by morpheme category and overall. Standard deviations are in parentheses. 516 international journal of american linguistics
TABLE 6 OBSERVED VOWEL DURATIONS BY MORPHEME TYPE
Duration (ms) Morpheme Vowel Length Mean (SD) Prefx Long 138 (52) Short 78 (47) Diphthong 119 (36) Stem Long 172 (92) Short 94 (44) Diphthong 159 (92) Overall Long 163 (90) Short 88 (50) Diphthong 196 (98)
Length diferences in Diné bizaad vowels are known to be robust (Mc- Donough 2003b), and in these recordings, Wilcox tests reveal a signifcant diference between Ms. Soulé’s long and short vowels overall (W = 472740, p < 0.001), within stems (W = 21678, p < 0.001), and within prefxes (W = 38588, p < 0.001). Diphthongs are also signifcantly longer than long vowels (W = 133220, p < 0.001). Figure 5 displays boxplots of the observed rhyme durations by syllabic posi- tion with long and short vowels combined. The dots above the boxes refect the many outliers present in these data. The mean of a word-fnal rhyme is 173 ms (SD = 116), that of an intonation unit-fnal rhyme is 221 ms (SD = 132), and the mean of a sentence-fnal rhyme is 224 ms (SD = 131). 13 Both intonation units and syntactic sentences appear to have longer rhymes in fnal position, though based on observed values, the rhyme durations in IU-fnal and sentence-fnal syllables are very similar to each other. Monosyllabic in- tonation units are also notably longer than other rhymes. Based on initial data exploration, rhyme duration measurements were log- transformed before ftting the statistical model. Since there is no signifcant diference between the duration of short vowels and the duration of syllabic nasals (W = 57430, p > 0.05), the two levels were combined because of a rela- tively low number of tokens of syllabic nasals (n = 106). Despite their longer durations, monosyllabic intonation units were removed because of low token numbers (n = 24), as were diphthongs (n = 198). After these adjustments, 2,624 syllables were included in the model selection process. A linear regression model was ft to the log-transformed rhyme duration using the methods described in 4.3. This model tested the hypothesis that
13 The means for long vowels in diferent positions are: word-fnal = 215 ms (SD = 129); IU-fnal = 275 ms (SD = 145); and syntactic sentence-fnal = 300 ms (SD = 79). The means for short vowels in diferent positions are: word-fnal = 133 ms (SD = 83), IU-fnal = 162 ms (SD = 93); and syntactic sentence-fnal = 67 ms (SD = 148). prosody in diné bizaad narratives 517
FIG. 5—Rhyme duration by syllabic position the duration of the syllable rhyme will be longer in unit-fnal position to mark the right edge of the boundary. The tested random efects were WORD, NARRATIVE, MORPHEME, and VOWEL LENGTH. The optimal random efects structure included both WORD and NARRATIVE as random efects adjustments to the intercept. The maximal model included fxed efects of POSITION IN WORD, POSITION IN IU, POSITION IN SENTENCE, their interactions with VOWEL LENGTH, and MORPHEME as an additive ef- fect. The fnal model (R2 = 0.292, R2c = 0.406) contained a fxed efect of MORPHEME and the signifcant interactions of POSITION IN WORD and VOWEL LENGTH and POSITION IN IU and VOWEL LENGTH. POSITION IN SENTENCE was removed from the model during the selection process. The complete model output, for this and all statistical models, is available in the appendix. Results from the model indicate that rhymes in IU-fnal position are pre- dicted to be signifcantly longer than rhymes in non-fnal position. IU-fnal rhymes with long vowels are predicted to be 254 ms, 87 ms longer than 518 international journal of american linguistics
IU-initial rhymes, and IU-fnal rhymes with short vowels are predicted to be 142 ms, 48 ms longer than IU-initial rhymes. The phonemic length contrast between long and short vowels is maintained despite the unit-lengthening ef- fect. There is no signifcant diference in rhyme duration between syllables in IU-initial vs. IU-medial positions. Rhymes are not predicted to be signifcantly longer in sentence-fnal position, despite the observed efects in fgure 5. Instead, these observed longer rhymes at the ends of syntactic sentences can partly be accounted for by the distribution of morphemes in sentence- fnal position: 63% of morphemes that occur syntactic sentence-fnally are stems. 14 The durations of rhymes are also predicted to be signifcantly difer- ent based on morpheme categories, independent of their position. Rhymes in stem morphemes are predicted to the longest, followed by prefxes, and then morphemes in the other category. The interaction between POSITION IN WORD and VOWEL LENGTH demonstrates that the rhymes of short vowels in word-initial position are predicted to be signifcantly shorter than syllables in word-medial position. Word-level prosody is not the focus of this paper, but this result could prove relevant for future studies. Results from a similar model ft to vowel duration instead of rhyme duration included slightly diferent efects. This fnal model (R2 = 0.382, R2c = 0.459) with WORD and NARRATIVE again as random efect adjustments to the in- tercepts, had a main efect of POSITION IN SENTENCE and the interactions of POSITION IN WORD and VOWEL LENGTH and POSITION IN IU and VOWEL LENGTH. The model predicts signifcantly longer vowels in fnal syllables versus non-fnal syllables of intonation units, and the lengthening is predicted to be much longer for long vowels than for short vowels: long vowels are predicted to be 208 ms in IU-fnal position, an increase of 72 ms over long vowels in initial syllables. Short vowels in IU-fnal position are predicted to be 100 ms, an increase of 30 ms over short vowels in IU-initial position. Since vowel length is contrastive in Diné bizaad, the amount that speakers can lengthen short vowels may be limited to avoid compromising the salience of the phonemic length distinction. A similar efect has been noted for Chickasaw, which also displays fnal lengthening and phonemic vowel length (Gordon and Munro 2007). Finally, this model included the prediction that short vowels in word-initial syllables will be shorter than short vowels in word-medial position. The vowel duration model essentially echoes the results from the model ft to rhyme duration, with the notable deviation that vowels in syntactic sentence-initial position are predicted to be the longest, followed by sen- tence-medial vowels, and then sentence-fnal vowels. The diferences between vowels in diferent syntactic sentence positions are relatively small; vowels in
14 As a point of comparison, only 39% of morphemes that occur IU-fnally are stems. prosody in diné bizaad narratives 519 sentence-initial position are only 15 ms longer than vowels in other positions, but this result suggests that Ms. Soulé marks the beginning of her syntactic sentences with a slightly but signifcantly longer frst vowel. A fnal diference between the models is that, although rhymes vary signifcantly in duration by morpheme type, vowels alone do not. This diference between the models points to some morphologically conditioned patterns of consonant lengthen- ing in these recordings, a pattern noted elsewhere in the literature on Dene languages (Young and Morgan 1987; McDonough 2003b; Bird 2004). Not much variance is explained by either random efect in these models; there is not much diference in rhyme or vowel durations based on narrative difer- ences or individual word-level efects. Beyond these statistical patterns, there are some noteworthy word-level patterns in the outliers. As is visible in fgure 5, Ms. Soulé has numerous data points that are longer than her typical rhymes, and although most of her rhymes are between 81 and 185 ms, her longest rhyme is 745 ms. Based on Ms. Soulé’s range and following a similar discussion in Lovick and Tuttle (2012), I consider rhymes greater than 250 ms to be examples of extreme lengthening, and thus Ms. Soulé has 334 tokens of extreme lengthening. The words that Ms. Soulé most frequently produces with extra-long rhymes are ńléí ‘there’, ’éí ‘that’, nít’ę́ ę́ ’ ‘then’, ’áádóó ‘and then’, and dóó ‘and’. These words all frequently serve discourse-level functions in Diné bizaad narratives and often occur at the beginning of syntactic sentences to mark episodic breaks or connect discourse events, as seen in (3) and (10). Intuitively, discourse markers provide logical targets for extra-long syllable rhymes as a way to emphasize a narrative juncture before launching into the description of the next event. 15 Furthermore, the presence of these extra-long words in sentence- initial position likely contributes to the model’s prediction of longer vowels at the beginning of syntactic sentences. 5.3. Interim summary of timing correlates. The results of an analysis of pause and syllable lengthening—both rhyme and vowel lengthening— demonstrates that Ms. Soulé is marking intonation units with following pauses and with signifcant syllable-fnal lengthening. Syllables with long vowels are especially elongated. Ms. Soulé marks her sentences with longer following pauses, but no fnal lengthening of rhymes or vowels. Instead, vowels in the frst syllable of her sentences are predicted to be slightly longer than vowels in other syllables in the sentence. Ms. Soulé maintains a robust distinction between long and short vowels, even in lengthened vowels at unit boundaries. I now turn to the correlates of pitch lowering and pitch reset.
15 As a point of reference, overall her most common words are ńléí ‘there’ (n = 80), ’éí ‘that’ (n = 79), ’áádóó ‘and then’ (n = 76), ’áko ‘so’ (n = 69), and bilasáana ‘apple’ (n = 49). 520 international journal of american linguistics
5.4. Pitch lowering. Pitch lowering is analyzed through a comparison of F0 values taken 75% of the way through the syllable nucleus in diferent syllabic positions. Prior to the analysis, I removed syllables with missing F0 values, as well as the 123 tokens of syllable nuclei containing long vowels or vowel clusters with falling tone. As measured by a Wilcox test, the F0 of syllables in monosyllabic intonation units did not difer signif- cantly from the F0 of syllables in IU-fnal syllables (W = 4584, p > 0.05); therefore these levels were combined for intonation units. However, the F0 of monosyllabic words did difer signifcantly from word-fnal syllables (W = 105510, p < 0.01), so the 398 monosyllabic words were retained as a separate level in the analysis of words. This left 2,287 syllables to further analyze, including 1,202 high-tone syllables and 1,051 low-tone syllables. For Ms. Soulé, the F0 of most low-tone tokens falls in a range from 144 to 173 Hz with a mean F0 for low-tone vowels of 158 Hz (SD = 28). For high-tone syllables the range is 163–201 Hz with a mean of 182 Hz (SD = 35). As expected, the diferences between high and low-tone F0 values are signifcant (W = 968800, p < 0.001). Table 7 shows the means and standard deviations for F0 values observed in each position, and fgure 6 displays these observed values as boxplots. The boxplots in fgure 6 show that F0 values are fairly stable across syllables in diferent positions in the word. In intonation units, syllables in the initial position have the highest F0 with a slight drop to a lower F0 in medial position. Intonation unit-fnal syllables have a still lower F0, though not much lower than those in the medial position. Similarly, in syntactic sentences the initial-syllable F0 is the highest followed by medial, and then the lowest F0 in sentence-fnal position. Both high and low tones exhibit pitch lowering in syntactic sentence- fnal position with observed median values that are very close to the bottom of Ms. Soulé’s typical pitch range for each respective tonal target. I followed the same procedure described in 4.2 to ft a mixed-efects model to F0 values. The optimal random efects structure was identifed after consid- ering random efects of WORD, NARRATIVE, TONE, and MORPRHEME. The optimal random efects structure again included WORD and NARRA- TIVE as random efects adjustments to the intercept. The maximal model included F0, as the dependent variable and fxed efects of POSITION IN WORD, POSITION IN IU, POSITION IN SENTENCE, their interactions with TONE, and MORPHEME as an additive efect. This model also includes the predictor DISCOURSE FUNCTION based on observations during prelimi- nary data exploration of Ms. Soulé audibly raising her pitch when quoting characters. After model selection, the fnal model (R2 = 0.163, R2c = 0.3081) contained fxed efects of POSITION IN IU, POSITION IN SENTENCE, DISCOURSE FUNCTION, MORPHEME, and the interaction between POSI- TION IN WORD and TONE. prosody in diné bizaad narratives 521
TABLE 7 MEAN (SD) F0 VALUES IN EACH POSITION
Initial Medial Final Monosyllabic Word High 183 (35) 187 (35) 177 (38) 177 (39) Low 160 (28) 151 (26) 154 (31) 153 (31) Intonation Unit High 185 (37) 181 (36) 175 (36) 175 (56) Low 164 (28) 154 (28) 151 (29) 161 (14) Sentence High 182 (37) 181 (37) 167 (29) Low 167 (34) 156 (28) 141 (24)
FIG. 6—Observed F0 values by syllable position 522 international journal of american linguistics
The model predicts a small, but signifcant diference in pitch for syllables in IU-initial position versus IU-medial syllables: the F0 value of IU-initial syllables is predicted to be about 7 Hz higher than medial syllables regardless of lexical tone. In syntactic sentences, F0 values are predicted to be around 10 Hz lower in fnal position when compared with medial syllables; again, this efect is shown to operate independent of lexical tone due to a lack of sig- nifcant interaction with TONE in the model. For the predictor DISCOURSE FUNCTION, values for quoted speech are predicted to be 10 Hz higher than asides and main speech. For MORPHEME, there is a small, but statistically signifcant diference between F0 values in prefixes when compared with morphemes in the other category, as well as a small but signifcant diference between stem morphemes and morphemes in the other category. Morphemes in the other category are predicted to have the highest F0 followed by stem morphemes and then prefix morphemes. Lastly, at the word level, high-tone medial syllables are predicted to be higher than high-tone syllables in other positions in the word. The random efects in this model, especially WORD, explain more variance than in the models ft to syllable lengthening; lexically specifc pitch patterns are expected given the presence of lexical tone. Together these results demonstrate that Ms. Soulé is marking the beginning of her intonation units with a higher F0 and the ends of her sentences with a lower F0. These pitch movements are small, but statistically signifcant. As seen in the observed values in table 7, though these efects operate across both tone levels, Ms. Soulé maintains a diference of around 20–25 Hz between her low and high tones in all positions; there is no evidence of the contrast neu- tralization that has been reported for boundary tones in some Dene languages (Holton 2005). Results confrm the observation that Ms. Soulé raises her pitch in quoted speech, ofsetting moments of dialogue from other parts of the nar- rative and making the narrative livelier and more animated. A brief examination of the 447 outliers in these narratives, in this case syllables with F0 values above 200 Hz, reveals that extra-high syllables occur most frequently with the words:’áádóó ‘and then’ hádą́ ą́ ’léiya ‘one day’— the frst word in four out of nine of these narratives—ńléí ‘there’, ’éí ‘that’, and nít’ę́ ę́ ’ ‘then’. These words overlap with those that contain extra-long syllables, listed at the end of 5.2, and thus Ms. Soulé may be emphasizing these words through syllable lengthening, as well as an elevated F0. 5.5. Pitch reset. The fnal correlate is pitch reset, closely related to pitch lowering, as the perception of a reset comes from either a fall at the right edge of a unit, a rise at the beginning of a unit, or both. In this study, pitch reset is operationalized as the diference in mean F0 values between each two contiguous syllables to refect the transition in pitch from syllable to syllable. A negative value refects a pitch fall from one syllable to the next, and a positive value refects a pitch rise or return to a higher baseline. Table 8 shows the distribution of lexical tone by position. prosody in diné bizaad narratives 523
TABLE 8 DISTRIBUTION OF LEXICAL TONE BY UNIT POSITION
Initial Medial Final Monosyllabic Word High 358 266 412 276 Low 514 340 441 111 Falling 33 25 54 11 Intonation Unit High 310 693 289 20 Low 245 902 255 4 Falling 21 59 43 Syntactic Sentence High 158 1070 84 Low 44 1257 105 Falling 9 92 22
Given the imbalance in the distribution of lexical tone by unit position, there is a confound with pitch reset; pitch movement from a low-tone syllable to a high-tone syllable is expected to be greater than a pitch movement from two syllables that share the same tone target. However, statistical t-tests show that there is no signifcant diference in pitch reset values when an intonation unit-initial syllable has a high-tone compared with when it a syllable has a low-tone (t = 0.13962, df = 55.615, p > 0.05). The same result holds for high and low-tone syllables in syntactic sentence-initial positions (t = −0.95681, df = 145.44, p > 0.05). These tests indicate that pitch reset values are not signifcantly diferent based on the specifcation of the unit-initial boundary tone; an efect of pitch reset should still be observable despite an imbalanced distribution of lexical tones. After removing missing values and syllables with falling tones, 2473 syl- lables remained for analysis. Figure 7 shows the observed reset values by syllable position. There is no observable diference in pitch reset by word position, whereas there is a visible pattern of initial reset in both the intona- tion units, by a median of 11 Hz, and the sentences, by a median of 21 Hz. These fndings complement the pitch lowering results discussed in 5.3. In intonation units, monosyllabic syllables are not signifcantly diferent from fnal syllables in pitch reset values; therefore, these categories were collapsed for intonation units, but not for words in which monosyllabic syllables are signifcantly diferent from fnal syllable positions in pitch reset values. Following the same model procedure utilized above, a model was ft to reset values measured in Hz. Tested random efects include NARRATIVE, TONE, MORPHEME, and WORD, but the models with random efects were not signifcantly better than models without random efects, so the model was ft without random efects. The maximal fxed efects structure included POSITION IN WORD, POSITION IN IU, POSITION IN SENTENCE, their interactions with TONE, and MORPHEME as an additive efect. The fnal model (R2 = 0.1072) included no interactions, and fxed efects of POSITION 524 international journal of american linguistics
FIG. 7—Observed pitch reset by syllabic position
IN IU, POSITION IN SENTENCE, TONE, and MORPHEME. Results show that for intonation units and syntactic sentences, there is signifcant evidence of a reset in pitch in initial syllables. For MORPHEME, stems and prefxes show a small but signifcant reset when compared with morphemes in the other category, which the model predicts to have a slight drop in pitch. Lastly, TONE is included as a main efect; unsurprisingly there is an overall pat- tern of a pitch rise when the second of two syllables has a high-tone and an approximately equal pitch fall when the second of two syllables has a low- tone, irrespective of unit position. Overall the results for pitch reset show no large diferences between con- tiguous syllables, though signifcant pitch movements occur at the beginning prosody in diné bizaad narratives 525 of intonation units and at the beginning of syntactic sentences. The model predictions are fairly small: a predicted reset of around 9 Hz for sentence- initial syllables and 10 Hz for intonation unit-initial syllables. There is no evidence of large pitch excursions consistently occurring between adjacent syllables, a result that may contribute to why native speakers have the intuition that Diné bizaad sentences have a relatively fat intonation. However, large pitch excursions are possible; 439 syllables, 18% of these data, have a pitch diference greater than 50 Hz between syllables. Thus far, no clear trends emerge in the patterning of these large local pitch movements. 5.6. Interim summary: Pitch correlates. The correlates of F0 mea- surements and pitch reset point to evidence of pitch lowering at the end of syntactic sentences accompanied by a pitch reset in the initial syllable posi- tion. A slightly larger pitch rise is also found at the beginning of intonation units. Contrasts between lexical tones are retained alongside these patterns.
6. Discussion. Returning to the documented observations about Diné bizaad prosody noted in 3, this study provides quantitative support for claims of syllable lengthening in intonation units (Kiser 2014) and a lower pitch at the ends of sentences (Landar 1963; Mithun 2008). Also, in 5.1 pauses were found to mark intonation units and syntactic sentences. Al- though word-level prosody is not a focus here, I fnd evidence of shorten- ing in word-initial short syllables. After the individual acoustic correlates are considered, table 9 summarizes the results at the boundaries for each investigated discourse unit. A checkmark indicates the presence of the in- vestigated correlate. These results support previous fndings that intonation units and a larger sentence unit are marked by similar timing and pitch correlates across lan- guages. More strikingly, these results closely match those of Lovick and Tuttle (2012), who found story units, similar to syntactic sentences, marked by fnal pause and pitch lowering, and intonation units marked by fnal pause and rhyme lengthening. Ms. Soulé realizes comparable patterns of rhyme lengthening and pitch manipulation, while maintaining phonemic distinctions of vowel length, lexical tone, and the phonological prominence of stems with
TABLE 9 SUMMARY OF SIGNIFICANT PROSODIC CORRELATES AT UNIT BOUNDARIES
Rhyme lengthening Pause Pitch lowering Pitch reset Word Intonation Unit Syntactic Sentence 526 international journal of american linguistics longer rhymes and a slightly raised pitch. These results are consistent with previous studies on Diné bizaad which have thoroughly described a close connection between morphology and phonology; both timing and pitch are said to play a role in delimiting morphological domains particularly within the verb word (McDonough 2003b). Nevertheless, the present study suggests that in addition to word-level prosody, Ms. Soulé also manipulates her timing and pitch to align with intonation units and syntactic sentences. The results reported in 5.3 and 5.4 match descriptive observations about a lower pitch at the ends of Diné bizaad sentences and do not corroborate the result of a lack of intonation found in elicited materials (McDonough 1999, 2003a). The patterns here point to small but systematic patterns of pitch lowering at the end of syntactic sentences and unit-initial reset, which would be inconsistent with the argument put forth in McDonough (2003a) that Diné bizaad, by virtue of its syntactic typology, has no fnal pitch rises or falls that may be evidence for intonation or boundary tones. Instead the results here provide further support for a low boundary tone (L%) marking the end of declarative sentences in Dene languages (Rice 1989; Holton 2005; de Reuse 2006; Schwiertz 2009; Lovick and Tuttle 2012). Beyond examining the targeted prosodic correlates, this study also points to stylistic patterns in how Ms. Soulé tells stories. The high pitch associated with quoted speech in these narratives is particularly salient and may pres- ent an example of what Landar (1959) calls supraregistration: “a raising of habitual pitch levels for high and low pitches alike, corresponding sometimes to anger, surprise, vivaciousness, and the like” (Landar 1959:11). Ms. Soulé further seems to be marking individual words, especially connector words at the beginning of syntactic sentences, with slightly lengthened syllables and raised pitch. Since the genre of Diné bizaad personal narratives remains less studied than other areas of grammar (but see McCreedy 1983), patterns in styles of spontaneous storytelling have not been thoroughly documented and provide an interesting avenue for future investigation. Though only based on the speech of a single narrator, this study has estab- lished a baseline for future investigations on prosodic correlates in Diné bizaad narratives recounted by more speakers. The analysis identifes signifcant cor- relates for Ms. Soulé’s narrations, but a signifcant amount of variance is yet to be explained in these models, suggesting there is much more to be learned about prosody even for this individual speaker. In particular, there is more to be understood about Diné bizaad intonation; the pitch correlates measured in Ms. Soulé’s speech are less robust than her timing correlates, and quantitative patterns of discourse unit-internal intonation have not been analyzed. In conclusion, this study presents the frst quantitative documentation of prosody in Diné bizaad narrative discourse through an analysis of the acoustic correlates of prosody at discourse unit boundaries. The results indicate the prosody in diné bizaad narratives 527 consistent use of following pause, rhyme lengthening, and small but signif- cant pitch lowering and initial resets to mark intonation units and syntactic sentences. These fndings provide quantitative support for earlier descriptive claims and demonstrate that with regards to prosody, the Diné language may not be as unusual as previous studies focused on sentence-level intonation have observed, though robust prosodic correlates may only emerge in con- tinuous discourse.
Appendix
TABLE A1 MODEL FIT TO RHYME DURATION: RANDOM EFFECTS Groups Variance SD WORD (intercept) 0.02767 0.1664 NARRATIVE (intercept) 0.01662 0.1289 Residual 0.22993 0.4795
N = 2,624; groups: WORD, 500; NARRATIVE, 9
TABLE A2 MODEL FIT TO RHYME DURATION: FIXED EFFECTS (SIGNIFICANT EFFECTS ARE Bolded) Estimate SE df t Intercept 5.151 0.05274 13.60 97.671 POS_WORD fnal_vs_nonfnal −0.1725 0.04243 2575 −4.066 POS_WORD initial_vs_medial −0.03594 0.04741 2434 −0.758 POS_IU fnal_vs_nonfnal 0.3386 0.03563 2579 9.505 POS_IU initial_vs_medial 0.4180 0.05802 2577 7.205 VOWEL_LENGTH_Short −0.5445 0.02773 2366 −19.636 MORPHEME_Prefx 0.10950.033859125 3.235 MORPHEME_Stem 0.21470.03104 9.584 6.915 POS_WORD fnal_vs_nonfnal: VOWEL_LENGTH_Short 0.03147 0.05419 2569 0.581 POS_WORD initial_vs_medial: VOWEL_LENGTH_Short 0.1697 0.06033 2390 2.813 POS_IU fnal_vs_nonfnal:VOWEL_LENGTH_Short −0.1333 0.04605 2585 −2.896 POS_IU initial_vs_medial:VOWEL_LENGTH_Short −0.05079 0.07824 2596− 0.065
TABLE A3 MODEL FIT TO VOWEL DURATION: RANDOM EFFECTS Groups Variance SD WORD (intercept) 0.021226 0.1457 NARRATIVE (intercept) 0.004238 0.0651 Residual 0.169797 0.4121 N = 2503; groups: WORD, 499; NARRATIVE, 9 528 international journal of american linguistics
TABLE A4 MODEL FIT TO VOWEL DURATION: FIXED EFFECTS (SIGNIFICANT EFFECTS ARE Bolded) Estimate SE df t Intercept 5.045 0.03205 24.70 157.419 POS_WORD fnal_vs_nonfnal −0.1151 0.03637 2426 −3.166 POS_WORD initial_vs_medial 0.007442 0.03949 2279 0.188 POS_IU fnal_vs_nonfnal −0.4714 0.04222 2480− 11.167 POS_IU initial_vs_medial 0.08774 0.04282 2486 2.049 VOWEL_LENGTH_Short −0.6491 0.02432 2264 −26.689 POS_SENTENCE_fnal_vs_nonfnal 0.1002 0.04449 2482 2.252 POS_SENTENCE_initial_vs_medial 0.09091 0.04239 2446 2.145 POS_WORD fnal_vs_nonfnal: 0.05892 0.04731 2457 1.245 VOWEL_LENGTH_Short POS_WORD initial_vs_medial: 0.1795 0.05290 2290 3.393 VOWEL_LENGTH_Short POS_IU fnal_vs_nonfnal: 0.1467 0.05537 2486 2.649 VOWEL_LENGTH_Short POS_IU initial_vs_medial: −0.1485 0.05290 2486 −2.807 VOWEL_LENGTH_Short
TABLE A5 MODEL FIT TO F0 MEASURED AT A POINT 75% INTO THE SYLLABLE NUCLEUS: RANDOM EFFECTS Groups Variance SD WORD (Intercept) 149.50 12.227 NARRATIVE (Intercept) 38.06 6.169 Residual 893.25 29.887 N = 2,287; groups: WORD, 488; NARRATIVE, 9
TABLE A6 MODEL FIT TO F0 MEASURED AT A POINT 75% INTO THE SYLLABLE NUCLEUS: FIXED EFFECTS (SIGNIFICANT EFFECTS ARE Bolded) Estimate SE df t (Intercept) 183.4662 4.3327 104.6 42.344 MORPHEME_Prefx−12.5931 2.4355 925.2 −5.171 MORPHEME_Stem −7.8313 2.2655 952 −3.457 TONE Low −19.6908 2.6073 2220 −7.552 POS_IU fnal vs nonfnal 3.3858 1.6645 2181.6 2.034 POS_IU initial vs medial −6.3544 2.8057 2222.3 −2.265 POS_WORD medial 5.6414 3.0251 2263.4 1.865 POS_WORD fnal− 4.0555 2.8685 2234 −1.414 POS_WORD monosyllabic −4.8917 3.5880 1426.5 −1.363 POS_SENTENCE fnal vs nonfnal 7.5665 3.6367 2260.2 2.081 POS_SENTENCE initial vs medial −4.2411 2.9681 2166.9 −1.429 prosody in diné bizaad narratives 529
Main Discourse 0.5373 2.8907 1989.3 0.186 Quoted Discourse 10.9450 3.9070 1815.5 2.801 Low tone: POS_WORD Medial −10.8282 3.8094 2258.1 −2.843 Low tone: POS_WORD Final −0.8181 3.6894 2187.2 −0.222 Low tone: POS_WORD Monosyllabic −5.5024 5.3754 1856 −1.024
TABLE A7 MODEL FIT TO PITCH RESET VALUES: FIXED EFFECTS (SIGNIFICANT EFFECTS ARE Bolded) Estimate SE t (Intercept) 12.4683 1.5452 8.069 POS_IU fnal_vs_nonfnal 4.7233 2.1759 2.171 POS_IU initial_vs_medial 12.5880 2.1293 5.912 TONE Low −20.0207 1.4953 −13.389 POS_PS fnal_vs_nonfnal −0.5034 3.6508 −0.138 POS_PS initial_vs_medial 10.6519 3.2675 3.260 MORPHEME_Prefx 4.6920 1.8842 2.490 MORPHEME_Stem 7.9308 1.8930 4.190
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