Effects of Position and Stress on English and Norwegian Vowel Quality

Home , Length (phonetics), Secondary stress, Stress (linguistics), Vowel reduction

Eﬀects of position and stress on English and Norwegian vowel quality∗

Anya Lunden [email protected] College of William & Mary June 2016

Abstract

Flemming and Johnson (2007) found a difference in vowel quality between unstressed vowels in non-final and word-final positions in English. The F1, F2 range of less-reduced word-final unstressed syllables is explored by through two production studies of (1) corner vowels in English and (2) /A/ in Norwegian. The word-final high vowels were found be show a small amount of undershoot in English, while the F1 and F2 of word-final unstressed /a/ was found to be in-between that of stressed [a] and [@]. Norwegian showed significant undershoot in unstressed syllables, with word-final unstressed syllables having an F1 in-between that of stressed and other unstressed [a]s. Word-final unstressed vowels in both languages were found to have an F1 that falls in-between that of stressed and non-final unstressed vowels; occurring as levels of phonological reduction in English and as phonetic reduction in Norwegian.

1 Introduction

English is known to reduce vowels in unstressed positions, typically to [@]. In contrast, Nor- wegian [@] is an unstressed allophone only of /e/ (Krisoffersen 2000:21). So unlike English, Norwegian /A/ is not known to reduce when unstressed. Two production studies are discussed, the first with American English speakers and the second with Norwegian speakers, with the purpose of examining the range of vowel quality associated with stressed vowels, non-final vowels, and word-final vowels within each language. The studies use nonce words with a consistent orthographic target throughout the word. Of particular interest is the phonetic realization of unstressed vowels in word-final position.

∗Thanks are due to Renee Kemp and Suzanne Franks for their assistance both in running the English study and in delineating the resulting sound ﬁles in Praat. Thank you to the audience at University of Indiana Linguistics Department for helpful comments and discussion relating to the English experiment and in particular to Ken de Jong and Kelly Berkson for helpful discussion.

1 In English, unstressed [i], [u], and [oU] are possible word-finally (e.g. ["hæpi] ‘happy,’ ["wIndoU] ‘window,’ [Im"pôAmptu] ‘impromptu’ (Chomsky and Halle 1968)). These vowels can surface unstressed in non-final positions only in phonetic contexts in which [@] cannot occur, mainly, immediately before vowels (e.g. ["eIli@n] ‘alien,’ ["ÃINoIzm] ‘jingosim,’ and ["AôÃu@s] ‘arduous;’ Chomsky and Halle 1968, Hammond 1999, Flemming" and Johnson 2007). In other non-final positions we expect /i/ and /u/ to surface in reduced form, generally taken

to be [@] (e.g. [ô@"f2nd]V ‘refund’; cf. ["ôif@nd]N). The low back vowel /A/ is reduced whenever it is unstressed in English, typically transcribed as [@] (e.g. [@"pôuv] ‘approve,’ ["pEô@saIt] ‘parasite,’ [@m"bôEl@] ‘umbrella’). Researchers have typically used [@] for all reduced/centralized vowel pronunciations in English (e.g. Chomsky and Halle 1968, Flemming 1993, Hammond 1997). Reduced vowels can have different realizations, however. Lass (1986) reports at least five varieties of schwa in his native (New York) dialect, described as being predictable based on place assimilation (e.g. a more back articulation due to an earlier [u] as in [wunR@d] ‘wounded,’ a more front articulation due to an earlier [i] as in [siR@d] ‘ceded’). Flemming and Johnson (2007) investigated reduced vowels acoustically and argued for a division into two categories: word-final [@] and non-final reduced vowels, which they found to have a significantly lower F1 (and thus are realized as a higher vowel). Flemming (2007) recorded word-medial reduced vowels in nonce words and found that the quality of the vowel was extremely susceptible to assimilation to its surroundings. The fact that the articulation of schwa can be so variable has led to the conclusion that schwa in fact has no target (Bates 1995). Browman and Goldstein (1992) analyzed the articulatory gestures associated with word-medial schwas and found them to vary based on the other vowels in the word, although with a pull toward a neutral position (where “neutral position” is not invariant but, rather, relative to the other vowels present). Flemming (2007) similarly concluded that the non-final reduced vowel has “at best a weakly specified vowel quality target.” The notion of schwa as being subjected to articulatory “undershoot” is discussed in the literature with two different perspectives, both of which differ from the original use of the term. Lindblom (1963) and Stevens and House (1963) first used the concept to refer to the relatively small degree of non-canonical pronunciation (usually phonetic centralization) that occurs in stressed vowels due to duration and consonantal context. In more recent literature it is common to find the term used with respect to phonologically reduced vowels as well. One discussed hypothesis is that schwa results from a kind of extreme undershoot of a full vowel (e.g. Steriade 1994, Silverman 2011). The second perspective de-links undershoot from the idea of centralization and instead uses it to describe the hypothesis that the variability of schwa is due to undershoot of its target as a mid-central vowel (e.g. Flemming 2007). All three notions of undershoot are potentially relevant in the current study. We will see that word-final unstressed vowels show the traditional notion of undershoot, whereas non- final unstressed vowels could be seen as being subjected either to what I will call “extreme undershoot” or to co-articulation (corresponding to the notion of undershoot of a mid-central target). The difference in quality of word-final vowels has received relatively little attention in the literature, but potentially has consequences for phonological differences of word-final syllables. While Norwegian has limited phonological vowel reduction, it may still show undershoot effects in unstressed syllables. Delattre (1969) shows that Spanish, which is known not to

2 reduce unstressed vowels (Crosswhite 2001), do show a measureable degree of undershoot in unstressed syllables. It is therefore likely to be the case in Norwegian as well. Of particular interest is whether we see a difference between non-final and word-final unstressed vowel qualities, parallel to the relative strength of word-final /A/ in English. The first experiment examines the effect of stress and position on the tense corner vowels of English. The quality of unstressed vowels is examined and the difference between non-final and word-final unstressed vowels confirmed. Although [A] does not reduce when unstressed in Norwegian, it is the vowel with the most room to do so. The second experiment is a production study with native Norwegian speakers which demonstrates different heights [A]; the most extreme articulation (that is, the highest F1) being that of a stressed [A], the next highest F1 being that of word-final unstressed [A]s, and the least extreme articulation, although still falling in the range we would expect for [A], occurring with non-final unstressed [A].

2 English Production Study

2.1 Method 2.1.1 Participants Subjects were 22 students (male=9, aged 19 to 23, mean age=20.6) from the University of Georgia. All were native English speakers. Participants were entered into a drawing for $50.

2.1.2 Stimuli Nonce words were constructed that consisted of CV syllables with the stress pattern σ"σσσ. There were four unique onset consonants in each word: [b], [d], [f], and [s]. The vowels were identical within a word: /i/, /u/, or /A/. There are 24 different possible orderings of four consonants and so 72 word types, given the three different vowels. This set was spit in half, with each list of 36 types balanced for an equal number of each syllable in each position, and with each other syllable preceding/following each syllable in each position. Each list was used with 11 subjects. The nonce words were placed as nouns into sentence frames of the form [Det N past-V the nonce-N that past-non-passive-RC], the relative clause ensuring that the nonce word would not be phrase final, thus limiting final lengthening to the word-level. In order to prevent special focus on the nonce word, the sentences were preceded by a question. Subjects read both the question and the answer.

Example task item

Which baDAfasa did her brother notice? Her brother noticed the baDAfasa that smelled funny.

Possible frame sentences were created and the researcher and two research assistants independently rated them for naturalness. The twelve most natural were triplicated, and 22 diﬀerent lists were created by randomizing the sets of 36 test words into the sentence frames,

3 duplicating them, and randomizing the resultant sentences. Sentences were manually moved if two using the same frame occurred in a row. Three ﬁller sentences with nonce words were placed at the end, resulting in sets of 75 sentences.

2.1.3 Procedure Subjects were given instructions that they were to read sentences containing a nonce word, and told to pronounce the nonce word with the same stress pattern as in the words Am´erica and asp´aragus. Before reading the question/answer pairs they practiced saying example nonce words with the target stress pattern. Subjects then received the printed list of test sentences and were asked to look at each sentence before reading it aloud as naturally as possible. Recordings were made in a sound-attenuated booth using a dynamic mic via a USB Pre to a MacMini into Praat (Boersma and Weenink 2016). A researcher listened during the recording, marking any sentences that were skipped, or in which the target word was mispronounced, and subsequently asked the subject to re-read those sentences. Rereadings were asked for a maximum of two times.

2.1.4 Measurements The vowels of the test word in the answer-sentence of the second instance of each question/answer pair were delineated in Praat. The vowel onset was measured from the beginning to the end of the regular wave form pattern, in conjunction with examining the spectrogram and intensity curve. If the second question/answer pair was missing or unusable, the first instance was used. Vowels were measured from the onset to the offset of a regular waveform. Mispronounced test words were not delineated. The most common problems were metathesis (e.g. bafasada rather than bafadasa), [I] for [i] in stressed syllables (in words like dif´ısibi), and test-word internal or adjacent pauses. This resulted in 537 words (2148 vowels) (cf. elicited 792 words; 3168 vowels). The midpoints of F1, F2, and F3 were measured for each vowel using a Praat script (Lennes 2003). While delineating the sound files, researchers noted that some tokens seemed to be pronounced with secondary stress on the final syllable. To quantify this, the intensity of the final vowel was calculated as a percentage of the stressed vowel, and subsequently averaged by subject.1 The majority of subjects’ average intensity proportions fell in the range of 0.93 to 0.94. Five subjects’ final vowels had notably higher intensity proportions, ranging from 0.97 to 1.02, suggesting the presence of secondary stress on the final syllable. The data from these five speakers were removed, leaving 407 words (1628 vowels) from the remaining 17 subjects. Spurious formant measurements were removed via identification of extreme outliers of F1, F2, and F3, normalized by subject and vowel. Cases > |3.29| were excluded. The remaining cases were normed by subject, and again outliers were removed, resulting in a dataset of 1622 vowels. 1Intensity measurements taken via Praat script (Hirst (2009))

4 2.2 Results Formant averages (Hz) are given for each vowel in each position in Table 1.

Table 1: Formant averages: Antepenult stressed, other positions stressless Female speakers F1 SD F2 SD F3 SD N /i/ initial 429.1 58.4 2008.5 182.2 2942.3 238.8 63 antepenult 338.3 47.0 2658.1 196.6 3127.5 250.3 63 penult 408.2 57.4 2216.2 252.4 2941.2 252.4 63 final 352.3 30.2 2664.7 205.2 3125.7 245.9 63 /u/ initial 422.0 59.0 1882.0 209.7 2835.9 232.7 67 antepenult 396.9 44.5 1887.0 269.6 2625.4 198.5 70 penult 416.3 45.8 1879.5 210.3 2735.5 231.9 70 final 394.3 35.8 1899.1 239.3 2636.4 224.4 70 /A/ initial 532.7 67.7 1720.1 184.6 2849.0 254.7 74 antepenult 884.1 61.4 1429.6 98.3 2588.3 181.7 74 penult 558.8 81.4 1700.7 171.8 2827.9 261.4 74 final 790.1 82.7 1567.8 131.6 2692.9 212.2 74

Male speakers F1 SD F2 SD F3 SD N /i/ initial 371.6 42.3 1778.3 196.5 2571.2 138.4 51 antepenult 329.5 34.1 2189.1 119.1 2710.3 150.3 51 penult 352.4 39.2 1878.7 172.5 2549.1 137.5 51 final 334.6 24.3 2141.2 121.7 2630.7 119.8 51 /u/ initial 336.7 31.8 1546.4 192.1 2411.3 153.0 73 antepenult 358.2 26.5 1581.3 204.6 2268.4 140.2 75 penult 358.5 32.2 1577.5 167.7 2383.1 149.0 75 final 361.1 21.0 1648.2 198.3 2297.0 138.4 74 /A/ initial 448.5 60.6 1379.6 171.4 2500.1 153.4 74 antepenult 698.5 46.9 1156.0 82.2 2432.4 154.0 74 penult 474.6 61.5 1294.0 145.5 2457.2 121.1 74 final 624.4 54.3 1219.5 138.9 2435.4 174.8 74

Formant measurements were normed by subject, in order to allow comparison between male and female subjects. Linear models were fit in SPSS using Generalized Linear Model function; given in Table 2. Each model considered a different dependent variable: z-F1, z-F2, z-F3, although the last will only be discussed for /u/. All models had factors position (4 levels: initial, antepenult, penult, final), vowel (3 levels: /A/, /i/, /u/), and and consonant (4 levels), as well as their interaction terms. The onset consonant that preceded each vowel was included in the models because of its often significant effect, but the effects are not

5 discussed further.2 Additionally, each model contained subject as a blocking factor, which was needed even with normed data because subjects ended up with unequal numbers of the different vowels in their final data sets. Post hoc pairwise comparisons of the estimated means for vowel∗position are the source of significance values reported in the text.

Table 2: Linear models of English data z-F1 z-F2 (Intercept) χ2(1) =39.657 < 0.001 χ2(1) =80.305 < 0.001 vowel χ2(2) =11993.980 < 0.001 χ2(2) =5209.633 < 0.001 position χ2(3) =777.255 < 0.001 χ2(3) =157.889 < 0.001 consonant (C) χ2(3) =26.617 < 0.001 χ2(3) =220.158 < 0.001 vowel∗position χ2(6) =3880.427 < 0.001 χ2(6) =1070.554 < 0.001 vowel∗C χ2(6) =12.868 0.045 χ2(6) =86.373 < 0.001 position∗C χ2(9) =29.221 0.001 χ2(9) =12.781 0.173 vowel∗position∗C χ2(18)=20.707 0.294 χ2(18)=40.556 0.002 subject χ2(16)=247.268 < 0.001 χ2(16)=211.036 < 0.001

z-F3 (Intercept) χ2(1) =25.476 < 0.001 vowel χ2(2) =1122.860 < 0.001 position χ2(3) =35.910 < 0.001 consonant (C) χ2(3) =39.506 < 0.001 vowel∗position χ2(6) =289.276 < 0.001 vowel∗C χ2(6) =11.676 0.070 position∗C χ2(9) =18.983 0.025 vowel∗position∗C χ2(18)=11.581 0.868 subject χ2(16)=60.357 < 0.001

2.2.1 duration While there is a significant effect of vowel on duration, and a significant interaction of vowel and position, the relationships between the positions are consistent between all three vowel types. For all three vowels, the final vowel was in fact longer than the stressed vowel (p < 0.001); the stressed (antepenultimate) vowel was longer than non-final unstressed vowels (p < 0.001); and the duration of the non-final unstressed vowels (in initial and penultimate positions) were not significantly different from each other (pairwise comparisons of p = 0.465 and higher).

2Effects of the following consonant could not be considered in the models because not all positions had a following consonant. While both the preceding and following consonants affected vowel quality (i) all consonant combinations occur in all non-final positions and (ii) visual inspection of plots show that vowels in each position overwhelmingly pattern together compared to other positions.

6 (1) Vowel duration

As is to be expected, vowel duration correlates heavily with syllable stress, with the exception of the word-final vowel, where we see a strong effect of word-level final lengthening. This is not phrase-final lengthening, as the nonce words were followed by a relative clause that were part of the larger noun phrase, and only fluent pronunciations were included. We will see that these final vowels are weaker than the stressed vowels in all other measurements. As the position of a vowel is generally proxy for the stress-status of a vowel, the discussion of the results often refers to stress instead of position. The stressed vowel is synonymous with the antepenultimate position, and the non-final unstressed vowels are those in the initial and penultimate positions. The word-final unstressed vowel is, we will see, unique in several ways because of its position and therefore it is relevant to refer to it separately from non-final unstressed vowels. The overall vowel space is shown in Fig. 1. Each point represents the average for a particular vowel in a specific position, for a single subject. Thus, each of the 17 subjects contribute 12 points.

7 Figure 1: Overall vowel space, averaged by subject/position

We can see, as expected, that realizations of /A/ varied more than those of /i/ or /u/. We expect /A/ to be realized as [@] when unstressed, but we see a continuum of /A/ pronunciations between mid central and low back regions, rather than two groupings clearly representing [A] and [@]. The high vowels also show some variation, although /u/ exhibits a fairly tight distribution. Each vowel’s stressed and unstressed realizations are discussed in turn.

2.2.2 /A/ The distribution of the most variable vowel, /A/, is shown in Fig. 2. The positions are hence- forth plotted according to normed formant values. Each point is the mean for a subject’s /A/ in that position.

8 Figure 2: Realizations of /A/, averaged by subject/position

We see that the lowest and furthest back vowels are stressed [A]s. The highest and most centralized are the non-final unstressed [@]s. It is evident that the “trail” of F1 values between these two groupings is due to the realization of word-final unstressed /A/, which are in-between [@] and [A] in height and backness. Pairwise comparisons of all four positions vary significantly in both F1 and in F2 from all other positions (p ≤ 0.001). This is the case even for the two non-final unstressed positions: [@] in initial position is higher and less back than [@] in penultimate position. The difference between these two [@]s, however, pales in comparison to distinctness of the other comparisons, where we see much greater differences.

2.2.3 /i/ Looking at the realizations of /i/, we see two distinct groupings: what we can consider to be [i], occurring under stress and word-ﬁnally (and in penultimate position, for one speaker), and a reduced vowel, occurring in non-ﬁnal unstressed positions.

9 Figure 3: Realizations of /i/, averaged by subject/position

Vowels in word-final position have a higher estimated mean of F1, however, the difference does not reach statistical significance (p = 0.079). They do not greatly vary in F2 (p = 0.260). Both stressed and word-final vowels differ significantly from non-final unstressed vowels in both F1 and F2 (p < 0.001). Although the non-final unstressed vowels appear to form a group in the plot in Fig. 3, vowels in the initial syllable show significantly more centralization than those in the penultimate position, as the two non-final unstressed positions vary both in F1 and F2 (p < 0.001).

2.2.4 /u/ The realizations of /u/ were the most closely grouped of the three vowels examined. Because stressed [u] is expected to exhibit more rounding than an unstressed realization, F3 was examined and it was found to encode the clearest differences in the realizations of /u/. The plot in Fig. 4 shows F3 on x-axis instead of F2. While not as clearly split as other vowels, we can see that the stressed and final [u]s exhibited a lower F3 and therefore a higher degree of rounding (shown as being further to the right in the graph), than the two non-final unstressed vowels.

10 Figure 4: Realizations of /u/, averaged by subject/position

Pairwise comparisons of F1 find two height groupings: stressed and word-final vowels do not significantly differ (p = 0.884), nor do vowels in initial and penultimate position (p = 0.113). Stressed and word-final vowels are significantly higher than unstressed non- final vowels in initial position (p = 0.001), but not in penultimate position (p ≥ 0.073). Only vowels in word-final position vary significantly from the others in F2 (p ≤ 0.037), as word-final vowels are somewhat more forward than the realization of /u/ in the other three positions. The clearest distinctions among realizations of /u/ are found with regards to F3. The graph above shows a divide like the ones we have seen before, between stressed and final vowels on the one hand, and unstressed non-final vowels on the other hand. There is not a significant difference between stressed and final vowels (p = 0.180), but both vary significantly from the non-final unstressed vowels (p < 0.001). There is a significant difference between the two unstressed non-final vowels (p = 0.002). As we saw for F2 with /A/ and /i/, it is the vowel in initial position that is showing the more reduced articulation, in this case a higher F3.

2.3 Reduced vowel comparison Thus far, positions have been considered only within vowels, but we now turn to a comparison of the reduced realizations across the vowels. All three vowels are most centralized in initial position, but these reduced vowels are still distinct, as can be seen from the plot in Fig. 5.

11 Figure 5: By subject averages of initial position by vowel

Unstressed initial realizations of /A/ are significantly different from both high vowels (p < 0.001) but the two high vowels do not differ in F1 (p = 0.312). Initial-syllable realizations of all three vowels differ significantly in F2 (p < 0.001), where the mean F2 of /u/ falls in-between those of /i/ and /A/.

2.4 Overall English vowel quality comparison The plot in Fig. 6 shows a single point for each vowel/position, which is an average of the subject averages of each vowel in each position. Putting aside the highly-clustered data points for /u/ (this vowel will be discussed separately), we can see a mirrored distribution of the realizations of /i/ and /A/, albeit compressed for /i/. As has been reported, all positions within both vowels are significantly different, except the stressed and word-final realizations of /i/.

12 Figure 6: Averaged subject averages by vowel/position

/u/

/i/

/a/

For both /i/ and /A/, the stressed realization is unsurprisingly the most extreme. The realizations of the three unstressed positions for each vowel follow the same pattern: The final vowel is the next most extreme, grouping more closely with the stressed vowel (and not significantly distinct from it in one of the two cases). The two unstressed non-final realizations visually group together for both vowels but, in both cases, the vowel in initial position has the most reduced/centralized articulation, with the unstressed penult being significantly closer to the more extreme pronunciation. As we saw in §2.2.4, the biggest difference we see for realizations of /u/ is in F3. A plot of F1 by F3 is given in Fig. 7 for /u/ and /i/ (included to give context to the /u/ data).

13 Figure 7: Averaged subject averages by vowel/position

/i/

/u/

Here we see that all realizations of /u/ do have a lower F3 (shown as being further to the right in the vowel space) than all realizations of /i/. And we again find the same distribution of vowel quality: /u/ pronounced in the initial syllable is the most reduced, just as initial /i/ and initial /A/ are. The penultimate vowel is significantly less reduced, while still visually grouping with the vowel in the initial syllable. Although the stressed and word-final realizations do not significantly differ for /u/ or /i/, we see visually that they fall in the same order as found with /A/, where the stressed syllable is the most extreme.

3 Norwegian Production Study

3.1 Method 3.1.1 Participants The data come from 14 adult native Norwegian speakers (male=6, aged 21-54, mean age=29.9) in the West Agder area in the south of Norway. Subjects were recruited through personal connections and did not receive any compensation.

3.1.2 Stimuli The stimuli were 23 three-syllable nonce words in a repeated carrier phrase. The nonce words, which were originally designed for a study on the relation between syllable weight and duration (Lunden 2013), had the basic shape katapa, with augmentations for diﬀer- ent syllable shapes and primary stress (indicated by capitalizing the target syllable); e.g. kaTApat, KANtapa, kataPATT, etc.

14 3.1.3 Procedure The stimuli were duplicated and the presentation order was randomized for each speaker. Subjects were instructed to read the sentences as fluently as possible and to pronounce the nonce word with the indicated stress and as if it were an actual Norwegian word. Subjects were recorded using a headset-mounted microphone, a Sennheiser PC130 (eight subjects) or a KOSS CS100 (6 subjects), connected via a Griffin iMic to a PowerBook G4 (first set of subjects) or a MacBook.

3.1.4 Measurement Nonce words pronounced as utterance-final (following pause, notable fall in intonation) were discarded. Four speakers read very few sentences fluently, as they had notable pauses before and/or after the nonce word. For one of these speakers, only two words remained his data set, and so that speaker’s data was completely removed. Readings where the end of the nonce word and the beginning of the next word could not be determined were also eliminated. The vowels of each syllable that did not have a nasal coda were delineated in Praat (Boersma and Weenink 2016), and coded for position and word stress. Although all stress denotations were possible in Norwegian, it was not uncommon for speakers to pronounce words with a different, more common stress pattern, and so nonce words were coded based on how they were actually pronounced. This yielded 1019 [A]s. The midpoint of F1 and F2 for each vowel was extracted with a script (Lennes 2003). The data was normed and z-scores > |3.29| were cut, resulting in a final dataset of 1014 vowels.

3.2 Results The formant averages (Hz) for vowels in each of the three positions are shown are shown in Table 3. They are broken out further by each of the three possible primary stress placements. When postion=word stress the vowel is stressed.3

3Stressed syllables in Norwegian must be heavy, resulting in vowel lengthening in the absence of a coda consonant. Long vowels can only occur under stress. Behne et al (1996) failed to find significant F1 or F2 differences between short and long [A] in Norwegian. The current data shows no difference in F1 between short and long stressed [A] and so they are collapsed here (Linear model; DV: F1 of stressed vowels, IVs: position (χ2(2) = 3.058, p = 0.217), length (χ2(1) = 0.005, p = 0.942), position ∗ length (χ2(2) = 5.087, p = 0.079)). Long vowels do have a significantly lower F2 than short vowels in all positions (DV: F2 of stressed vowels, IVs: position (χ2(2) = 22.550, p < 0.001), length (χ2(1) = 8.799, p = 0.003), position ∗ length (χ2(2) = 0.106, p = 0.948)).

15 Table 3: Formant averages

Female speakers position word stress F1 SD F2 SD N antepenult antepenult 866.7 99.1 1461.5 137.8 56 penult 789.2 101.5 1570.2 140.5 78 final 808.2 89.6 1512.7 134.4 82 penult antepenult 781.2 73.2 1452.2 145.4 73 penult 860.2 77.9 1420.7 134.9 67 final 771.4 55.2 1472.9 117.0 81 final antepenult 839.2 85.0 1358.7 132.0 79 penult 827.6 75.3 1373.9 105.8 78 final 875.5 79.5 1385.5 129.5 56

Male speakers position word stress F1 SD F2 SD N antepenult antepenult 719.9 99.3 1169.3 105.0 40 penult 663.5 88.1 1399.8 243.6 35 final 658.1 67.5 1316.9 238.1 45 penult antepenult 645.9 105.6 1303.5 323.0 52 penult 731.7 66.4 1159.0 129.7 27 final 631.9 76.0 1290.8 262.2 43 final antepenult 666.0 106.3 1226.4 307.6 55 penult 700.4 128.0 1374.0 460.5 32 final 711.0 94.9 1192.4 310.6 35

The plot in Fig. 8 shows the range of stressed and unstressed pronunciations of /A/ in English and in Norwegian for the female speakers in each of the studies. As expected, /A/ does not vary in quality in Norwegian to the degree it does in English. (Data points are averages by subject for four categories of vowel: In English, the four positions; in Norwegian, stressed, non-final unstressed, non-final secondary stress, and word-final unstressed).

16 Figure 8: English vs. Norwegian /A/ vowel space (female speakers)

F1 and F2 were normed by subject, as with the English data. Two linear models were ﬁt with these normed formant values as DVs, with position and stress and their interaction as factors, given in Table 4. (Subject was not included, since the standardization in this case accounted for inter-subject variability.)

Table 4: Linear Models of Norwegian data

z-F1 z-F2 (intercept) χ2(1)=4.009 0.045 χ2(1)=0.595 0.440 position χ2(2)=68.556 <0.001 χ2(2)=235.591 <0.001 stress χ2(2)=7.126 0.028 χ2(2)=20.858 <0.001 position∗stress χ2(4)=299.925 <0.001 χ2(4)=63.573 <0.001

The models consider all nine levels of position ∗ stress, but we have three grouping categories of interest: stressed vowels, completely unstressed non-final vowels, and word-final unstressed vowels. There is a potential for secondary stress, however, in antepenultimate vowels with final stress and in final vowels with antepenultimate stress. Pairwise comparisons find that antepenultimate vowels in final stress words do vary significantly in height from those in the same position in words with penultimate stress (p = 0.003) but not in backness (p = 0.284). On the other hand, unstressed final vowels do not differ in either F1 (p = 0.394) or in F2 (p = 0.214). Thus, there is some evidence from vowel quality for secondary stress in antepenultimate position but not in final position.4

4This agrees with Kristoﬀersen (2000) who describes secondary stress as occurring on every other syllable before the main stress, at least in some cases. The language description in van der Hulst et al (2010) also states that, with exceptions, secondary stresses occur on every other syllable before the primary stress.

17 We can therefore examine the vowels along four broad classifications: stressed, non-final unstressed, non-final secondary stressed, and final unstressed. The plot below shows the average across subject’s averages for each position with each possible stress (nine combinations), grouped into these four categories.

Figure 9: Averaged subject’s averages for position and stress

We see that stressed [A], regardless of the position it occurs in, has the lowest articulation. The three non-final completely unstressed [A]s (one from antepenultimate position, two from penultimate) have the highest articulations, and the F1 of the average antepenultimate [A] under secondary stress and the unstressed word-final [A]s are in-between these two. These two types of in-between [A] pattern differently for backness, however. The [A] bearing secondary stress groups with the unstressed [A]s in backness, whereas the word-final unstressed [A]s are further back, and appear closer to the stressed [A]s than the non-final unstressed or secondary stress realizations. Pairwise comparisons do show differences between some items within some of the broader groupings indicated by the four grouping symbols. For example, while the F1s of stressed syllables in each of the three positions were not significantly different (p ≥ 0.238), a stressed antepenult [A] is significantly less back than stressed [A]s in other positions (p ≤ 0.001). Because the data had a confound of consonant (each position had a unique, consistent onset) we do not know whether the differences within each grouping are due to position or are an effect of the surrounding consonants. In fact, it is likely that this difference in F2 is in fact due to the surrounding consonants since the vowel from the antepenultimate syllable also has a significantly higher F2 among non-final unstressed vowels (p < 0.001). These differences are small compared to the differences between the main stress/position groupings, however, and so the data was classified into the four stress/position groupings discussed, thus ignoring the differences between stressed [A]s, non-final unstressed [A]s, etc. The plot in Fig. 10 shows that the summary plots in Fig. 9 are representative of the data as a whole, with subjects’ average word-final unstressed [A] reliably falling in the mid-height range.

18 Figure 10: Averaged by subject/position-type

A linear model for z-F1 with only one factor, the collapsed set of stress and position combinations, finds significant differences between all four stress/position levels (χ2(3) = 376.073, p < 0.001). Pairwise comparisons show that primary stress resulted in a significantly higher F1 (p < 0.001) than found for unstressed or secondary stressed [A]. Word-final position shows the second-highest F1, which is significantly different from the next-highest, occurring under non-final secondary stress (p = 0.002). In turn, non-final secondary stress results in an F1 that is significantly higher than that of non-final unstressed vowels (p < 0.001). A second model, fit for z-F2, found that it is word-final unstressed vowels that have the lowest F2. While they show a significant difference from the F2 of stressed [A](p = 0.002), this is presumably due to the effect of including different neighboring consonants, as pairwise comparisons of the earlier model showed no difference in F2 between word-final stressed and unstressed positions (p > 0.544). Non-final unstressed [A] had a significantly higher F2 than either word-final unstressed or stressed [A](p < 0.001). Non-final unstressed [A] has a significantly lower F2 than found under non-final secondary stress (p = 0.002), however, once again there is reason to think this is due to differences in neighboring consonants, as pairwise comparisons from the earlier model with all levels of word stress and position show no difference in F2 between unstressed and secondary-stressed [A] in antepenultimate position (p = 0.284).

4 General Discussion

In English, word-final unstressed high tense vowels were close to their stressed realizations. While statistically, neither word-final [i] or [u] were significantly different from the stressed pronunciations, both vowels fell into a pattern where the stressed vowel had the the articulation most characteristic of a corner vowel, trailed by the word-final vowel, and then the non-final unstressed vowels (see Fig. 7 in §2.4). Word-final unstressed /A/, on the other

19 hand, was found to have a pronunciation that, while distinct from [A], had a notably higher F1 than the same target vowel in non-final unstressed positions. In Norwegian, we see a condensed parallel. While unstressed /A/ does not become the reduced vowel that it does in English, we do see more extreme pronunciations of the vowel when stressed and less extreme when unstressed. Further, and most notably, word-final unstressed [A] is realized with an F1 that is in-between that of stressed and non-final unstressed [A]s. The English word-final pronunciations of what should be [@] (unstressed /A/) were closer to [A] than were found for Flemming and Johnson (2007). The fact that the stimuli were nonce words with an orthographic target of ‘a’ in all syllables may have lead to more [A]-like pronunciations of unstressed syllables overall. However, a second possible factor might be that all of word-final [@]s in Flemming and Johnson’s study were taken from words that had penultimate stress. It may be the case that an unstressed syllable word-finally is weaker next to a stressed syllable, to contribute to the rhythmic alternation of the word. The differences among vowel qualities could be viewed as undershoot, especially as nonce words were presented in written form, meaning that there was an orthographic target given for each vowel, which was always the same as the stressed syllable. As word-final vowels fell just short of stressed vowel pronunciations, presumably because of their unstressed status, we can describe this as undershoot in the sense of Lindblom (1963) and Stevens and House (1963). All non-final unstressed vowels showed a degree of centralization consistent with phonological reduction. The continuum of reduced vowels in the unstressed initial and penultimate positions could be seen as two levels of extreme undershoot of a full vowel target. However, they could also be [@] showing coarticulation effects with the other vowels in the word (e.g. Cho 2004, Flemming 2007), and thus being pulled away from schwa’s canonical mid-center articulation. The difference between these two possibilities is relevant for understanding (i) whether vowels in these two unstressed positions (in conjunction with the stress pattern of these words) really do show a difference in degree of reduction and (ii) for clarifying whether the most reduced forms of the three vowels are distinct in the absence of vowel-to-vowel coarticulation. A potentially relevant study which used real English words, meaning the vowels varied within each word, is Fear et al (1995) who examined word-initial /i/, /u/, and /A/ with primary stress, secondary stress, unstressed but unreduced quality, and unstressed with reduced quality. They found a similar “stacking” effect, where primary stressed vowels had the most extreme articulations, followed by secondary stress, followed by unstressed unreduced, and finally unstressed reduced vowels. Raw F1, F2 values are not reported, however, so it is not possible to compare their word-initial unstressed reduced vowels with the values found in this study. The differences in vowel quality of non-primary stress vowels in Norwegian can be un- derstood as undershoot in the sense of Lindblom (1993) and Stevens and House (1963), as they are considered [A]s but have been shown to be somewhat phonetically reduced. I am not aware of any previous studies of Norwegian vowel quality by position; however, Nord (1986) compared unstressed initial and unstressed final-syllable vowels in Swedish. The final-syllable vowels were all followed by a coda consonant, and so they are not a direct parallel to the word-final vowels examined here. Nord’s four male speakers, pronouncing words in citation form, had a higher F1 in unstressed final-syllable [A]s than in unstressed initial-syllable [A]s (statistically significant, α = 0.05). Thus the present study is in line with this finding, and shows that this is also the case for [A] in open syllables that are not phrase-

20 final. Nord also examined realizations of /i/, /0/, and /e/, and found that these vowels in unstressed initial syllables in fact generally had more extreme pronunciations than they did in unstressed final syllables. This finding is surprising in the context of the present studies. Flemming and Johnson’s (2007) study of reduced vowels in English found that within the final syllable, a schwa followed by a coda consonant had a lower F1 than a schwa directly at the word boundary. So it is plausible to think the same is true for Norwegian/Swedish, albeit in the condensed space. It may therefore be the case that the non-low vowels show a greater degree of undershoot in final syllables when followed by a consonant than [A] does. A possible reason for this difference might be that the inherently longer duration of the low vowel allows it to reach a pronunciation closer to that of stressed [A] even though it was not directly word-final. We have seen that both English and Norwegian show a relatively strong pronunciation of word-final /A/ compared to non-final unstressed realizations. The realization of the high tense vowels in English suggest that undershoot is occurring, but are different from /A/ in that they are not phonologically reduced. Ideally word-final unstressed realizations would be investigated for other vowels but the orthographic constraints of English make it difficult to to test /e/, /E/, /æ/, etc.5 While both languages investigated show the same pattern, Johnson and Martin (2001), found the opposite effect in Muskogee Creek, in which unstressed word-final vowels showed greater centralization than unstressed vowels in initial syllables. It may be the case that languages differ in this respect; however, their study did not include a comparison between word-medial and word-final unstressed vowels and so it is possible that initial-syllable vowels show some kind of (additional) strengthening in Creek.

5 Conclusions

Two production studies showed the range of pronunciations of orthographic target vowels: the three corner vowels for English and the low back vowel for Norwegian. The English study used four-syllable words, with fixed stress on the antepenultimate syllable, whereas the Norwegian study used three-syllable words with varying stress. The claim that word- final unstressed high tense vowels do not reduce in English was also borne out. Word-final /i/ showed a somewhat higher F1, and word-final /u/ showed a somewhat higher F3; so both high vowels showed a small degree of reduction, neither of which reached statistical significance. Pronunciations of /A/ varied the most, and in this case word-final vowels were significantly reduced from stressed vowels, but significantly less reduced than non-final unstressed pronunciations. A regular pattern of progressing centralization was found with all three English vowels, as the vowels in initial syllables were significantly more centralized than vowels in penultimate syllables, although both were unstressed. The claim that /A/ does not seriously reduce in Norwegian was borne out, although phonetic undershoot was found in vowels without primary stress. Evidence from vowel quality for secondary stress was found for antepenultimate, but not word-final position. The finding of particular interest is that word-final unstressed vowels showed the least amount of undershoot. Realizations of /A/ in both English and Norwegian show a notable phonetic strength in word-final syllables,

5While /o/ can be communicated orthographically, it is like the high tense vowels, known to exist unstressed word-ﬁnally.

21 on diﬀerent scales of reduction.

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