Changing Perceptions: The Sociophonetic Motivations of the Labial Velar Alternation in Spanish

The labial-velar alternation is a prevalent feature of widely dispersed Spanish dialects (Colombia, New Mexico, El Salvador, Ecuador, Chile, and Mexico among others). The bilabial approximant [β] alternates with its velar counterpart [ɣ] when preceding the vowel [u] and the diphthongs [we], [wi]. Thus, a word such as abuelo ‘grandfather’ is realized as a[ɣ]uelo by children and speakers with low education. This phenomenon is intriguing, because it has been noticed long ago in the historical development of the language and it is still observed in speakers from disparate geographical areas. Although the labial-velar alternation has been observed within historical linguistics (Lloyd 1987, Penny 1991), it has not yet been subject to synchronic analysis neither within phonetics nor within sociolinguistics. Yet, the only way to truly understand the motivations and the mechanisms of sound change is to analyze the physical (articulatory and acoustic) characteristics of the sounds involved (i.e. phonetics), as well as the social aspects of language use (i.e. sociolinguistics). The purpose of this study is twofold: 1) to investigate the acoustic and perceptual motivations of the [β] > [ɣ] alternation and, 2) to examine its subsequent spread through the speech community. In other words, the aim is to study both the causes and the propagation of this variable linguistic phenomenon. I propose that the labial-velar alternation is triggered by the perceptual similarity of /b/ and /g/ in the context of round vowels and diphthongs [u], [we], [wi]. Articulatory and perceptual similarity cause confusion and confusion can lead to synchronic variation and eventual sound change (Ohala, 1992). I hypothesize that the spread of this variation to the upper layers of society is blocked by literacy, since orthography can help to resist perceptually driven sound changes. My work on consonants combines three methods of data collection: sociolinguistic interviews, production and perception experiments. A sociolinguistic interview aims at eliciting vernacular speech from different social groups. Thus, it provides important information on the degree of intra and interspeaker variation of a certain linguistic form. Since it is meant to be an informal conversation, the sociolinguistic interview is never conducted in a soundproof booth. Thus, a main disadvantage of interviews for the study of sounds is the lack of clarity of the recordings generally performed in people’s houses, work places or outdoors. Phonetic instrumental experiments, on the other hand, record data with high fidelity equipment in soundproof booths. However, the controlled activities (such as repetition and listening tasks) used to elicit speech and the intimidating environment of soundproof booths make it difficult, if not impossible, to obtain naturally occurring speech. This study combines all these methods of data collection (sociolinguistic interviews with acoustic and perceptual experiments) to overcome the limitations of using a single technique. This article is organized as follows; in section §2 I begin with a summary of the development of Latin /β/. Section §3 reviews the acoustic and perceptual characteristics of the approximants [β] and [ɣ]. I present my research questions and I review the theories of sound change upon which I base my analysis in section §4. The hypotheses are discussed in §5. The methods of data collection, the subjects