The objective of this dissertation is to explore the phenomenon ofdesdoblamiento vocálico or tense-lax vowel alternation in eastern Andalusian Spanish, particularly, in Granada Spanish and in the Spanish of Cartagena, Colombia. In previous studies of Eastern Andalusian Spanish (Navarro Tomás, 1939; Alonso et al., 1950; Mondéjar, 1970; Salvador, 1964, 1977) it has been claimed that in this variety of Spanish, vowels preceding deletion of post-nuclear /s/ undergo an open-closed vowel alternation. As a result, this vocalic alternation may serve as a functional marker distinguishing singular from plural in nouns and person-number in certain verbal forms rendered homophonous by the deletion of final /-s/.^ Following the methodologies of Hammond (1978), Figueroa (2000), and Carlson (2006), speech samples were elicited from ten native speakers of Granada Spanish and acoustically analyzed with Praat. In addition, a perception test was arranged with these speech samples and administered to twenty speakers of Granada Spanish. For the purpose of making a cross-dialect comparison, the experiment above was replicated with native speakers of Cartagena Spanish, another dialect well-known for its high rate of final /-s/ deletion (Becerra, 1985).^ This study found a significant tense-lax alternation for the non-high vowels preceding deleted final /-s/. The degree of alternation is the greatest for the vowel /e/. These findings concur with those of Llisterri and Poch (1987), Martínez Melgar (1994), and Sanders (1994). Regarding the perception portion of this study, results reveal that the rate of correct responses for items without a following /s/ is significantly higher than that of items with deleted final /-s/ in both dialects. These results indicate that, despite de tense-lax vowel alternation, participants failed to accurately identify items with deleted final /-s/. This degree of vowel alternation does not provide Granada Spanish speakers nor Cartagena Spanish speakers with sufficient acoustic cues for distinguishing between a vowel before deleted /s/ and a vowel without a following /s/. The results in this study do not support the claim that desdoblamiento vocálico or vowel alternation fulfills a phonemic function in eastern Andalusian Spanish. The same holds true for vowel restructuring in Cartagena Spanish
