A situation of language contact on the Uruguayan-Brazilian border has created a unique opportunity to study variant usage with respect to the phoneme /b/. Following past research models, the thesis analyzes the social and linguistic effects of contact bilingualism on the border variety of Spanish using acoustic phonetics. The intervocalic /b/ was the target variant in the study. Analysis was performed on the speech tokens of 20 speakers living on the Uruguayan-Brazilian border using the phonetics software Praat, and from the tokens the consonant-vowel intensity ratio of each intervocalic /b/ was determined in order to characterize the variant. The tokens were classified as one of four possible variants, [b], [v], [β], or phonetic zero. The thesis found that cognate status, normative Spanish orthography, and professional status were the significant predictors of variant usage.