PHONETICS AND PHONOLOGY PHONÉTIQUE ET PHONOLOGIE PHONETIC MOTIVATION FOR VARIATION IN SPANISH TRILLS 1. Introduction The vibrant, or trilled, [r] is a rather uncommon sound found in few contemporary languages (LADEFOGED et al. 1977: 49). It represents a highly salient pronunciation feature of Spanish which non-native speak- ers immediately recognize, but seldom master without great effort. The demanding production requirements of the vibrant make it the final speech gesture to be fully developed by native children (JIMÉNEZ 1987: 361). In the prestige dialect of Castile the trill consists of a series of brief occlusions made by the tongue tip against the alveolar ridge while the vibrating vocal cords sustain voicing (NAVARRO TOMAS 1967: 122). The acoustic impression of the trill is that of a vowel-like sound whose spectral characteristics approximate the vocalic segment it anticipates interrupted periodically by a non-aspirated stop element. In Spanish it is phonologi- cally distinct from the simple tap, also produced in the alveolar region, as illustrated below: (1) Spanish gloss Spanish gloss [koÍo] “choir” [koro] “I run” [paÍa] “for” [para] “vine” [qeÍo] “zero” [qero] “hill” Outside of Northern Spain and other conservative Spanish speech communities, the vibrant has undergone a wide range of phonetic adjust- ments resulting in articulations quite different from the norm. Two main variant forms serve as key features in the classification of regional speech habits. The assibilated phone [r] occurs when the tongue-tip gesture does not give rise to multiple occlusions, but rather creates a narrowing at the alveolar ridge with accompanying audible frication, similar in nature to the Czech fricative trill (LADEFOGED et al. 1977: 49). Palatographic evidence of speakers of Puerto Rican Spanish shows extensive lingual alve- olar contact in the lateral regions for [r], which suggests that the frication is centrally released (NAVARRO TOMAS 1966: 89). Alternatively, the point 52 K. WIDDISON of articulation may shift to the extreme back of the vocal tract resulting in a uvular phone produced as a vibrant [R], fricative [x], or approxi- mant [™] sound, depending on the degree and type of constriction. Unlike the normative trill, both of these phonetic variants, the assibilated and uvular phones, tend to devoice (CARDENAS 1958: 407; NAVARRO TOMAS 1966: 89). The phonetic metamorphosis of the Spanish vibrant affects a wide cross- section of language users. Field research shows the assibilated variant to be quite common in highland dialects including Paraguay, Ecuador, Peru, Bolivia, most of Argentina and Chile, Costa Rica, Guatemala, and the Mexican plateau (cf. CARDENAS [1958] for a detailed discussion of the distribution of [r]). While a velarized pronunciation of the vibrant is most often associated with Puerto Rican Spanish (NAVARRO TOMAS 1966: 94), it has also been found in other Caribbean dialects such as Cuba, Panama, and coastal Colombia and Venezuela (CANFIELD 1962: 91-92; CUÉLLAR 1971: 19). Within these speech communities, variant forms of the vibrant are found among diverse segments of society to a degree, at times, approaching majority status (GORDON 1987: 722-723; MORENO DE ALBA 1972: 366-367; TERRELL 1982: 62-63). The variation observed in Spanish vibrants may be described in terms of phonological processes such as assibilation, velarization, and devoic- ing. Yet these descriptive labels do not address the more interesting question regarding the root causes behind such shifts in pronunciation. There is wide agreement that the vagaries of the trill are the result of phonetic erosion occasioned by articulatory weakening, yet little more is known about the precise physical nature of the problem. Within many current linguistic theories, phonetic details are often considered irrelevant when conjecturing about the higher level forces that instantiate change. Moreover, research into the assibilation, velarization, and devoicing of the Spanish trill has been conducted as though these were separate, dis- connected issues. In this paper I set forth a phonetic basis for explaining the weakening of the Spanish vibrant by examining some of the key production aspects of trills and considering the interaction of these in the communicative process that requires language forms to be encoded and subsequently decoded. The working hypothesis is that changes occurring in place, manner, and voicing of the apical vibrant stem from natural physiologi- cal limitations in producing the aerodynamic event that characterizes the sound and that the resulting allophonic consequences are closely related. Before proceeding with this analysis, I will briefly review other accounts of the problem(s) and discuss the nature of general phonetic tendencies as they relate to the manifestation of sound change in particular language systems. PHONETIC MOTIVATION FOR VARIATION IN SPANISH TRILLS 53 2. Models of /r/ variation and change Formalist phonological theory maintains that the reasons for phonetic change transcend the mechanical operation of the speech and hearing appa- ratus. It is presumed that change occurs at a broader, systemic level of lin- guistic function independent of the day to day interaction of speaker-hearers. The stimulus for system-wide change may be internal, such as the exis- tence of structural imbalances or the development of cognitive processing inefficiencies, or external, as in the adoption of the language by new users with different linguistic backgrounds and communicative needs. A fairly common extralinguistic account ascribed both to /r/ velarization and assibilation centers on the influence of languages in contact with Spanish. The uvular [R] predominate in the Caribbean has been attrib- uted variously to French, African, and indigenous populations (CUÉLLAR 1971: 20). Likewise, the assibilated [r] is claimed to have arisen due to contact between Spanish and other systems such as Basque, English, and Native American languages (CARDENAS 1958: 412). Evidence for this assertion is rather tenuous due to the geographic spread of the phenom- ena when compared to the historical settlement patterns of these groups. For example, it has been found that in those areas where the adstrat influence was greatest, phonetic variation of the trill is minimal and vice-versa (NAVARRO TOMAS 1966: 94). One advantage of analyzing the data system-internally is that it pro- vides a more uniform account of phenomena that affect large groups of Spanish speakers. For example, DE GRANDA argues that the standing quantitative correlation between the tap and trilled alveolar phones, the latter viewed at least conceptually as a multiple occurrence of the for- mer, does not fit well with other contrasts in the adjoining phonological space (1969: 4). MALMBERG claims that the assibilation of the normative vibrant follows the historical pattern in Spanish to convert the Latin sim- ple-geminate distinction into one of quality, a change already realized on nasal and lateral sounds (1950: 142). With respect to [™], GUITART (1982) suggests that this articulatory backing conforms with a larger ten- dency affecting other phonemes in the system, such as commonly occurs in the case of s-aspiration (/s/ → [h]) and nasal velarization (/n/ → [∞]). Similar arguments appealing to general organizational principles that oversee the representation and retrieval of language forms may account for the same variation. For example, velarization of /r/ in Spanish may be analyzed as an adjustment in phonological rules and/or a simplifica- tion in the specification of features that introduce economies into the system. In either case, since the variation is motivated by factors which affect the entire language system it becomes easier to justify the wide- spread variation apparent in the data. 54 K. WIDDISON However, nonphonetic models such as those outlined above fall short of adequately explaining the variation exhibited by the Spanish trill in two important ways. First, they fail to recognize parallel developments in vibrant sounds occurring in other language systems. For example, velarization of trills is not unique to dialectal Spanish but also occurs in many areas of contemporary Brazilian Portuguese. In Parisian French, a uvular1 phone of recent historical origin has acquired prestige status while the older alveolar trill persists in the provinces. In fact, the same directional shift has occurred in dialects of many other European lan- guages for which the primitive form of /r/ was undoubtedly the vibrant, including German, Dutch, Danish, Swedish, Norwegian, and Northern Italian (MALMBERG 1963: 46). This cross-linguistic correspondence sug- gests that the causal forces motivating the pattern likely represent gen- eral phonetic tendencies constraining all language systems. A narrow, language-internal perspective runs the risk of missing this important generalization. It should be noted that a phonetic universal constraint that favors the velarization of alveolar trills does not imply that such a course of action must be realized in all relevant language systems. This is no more nec- essary than a claim that language-specific pressures must result categor- ically in a given variant throughout the entire speech community. A gen- eral phonetic tendency merely provides the impetus for eventual sound change to occur if the emerging habit gains societal acceptance. The fact that the change is carried out completely in some languages, incom- pletely in others, and not at all in others, is strictly