The Association Between Bilingualism and Voice Quality in Spanish-English Bilingual Speakers: A Systematic Review

The vast majority of the global population speaks more than one language. In the United States, Spanish-English bilingual speakers are the largest bilingual group. Yet, the potential effect of being bilingual, specifically a Spanish-English speaker, on voice quality is poorly understood. The current study consequently set out to systematically review the literature on the association between being a Spanish-English bilingual speaker and voice quality.

Systematic review.

A systematic review of association was conducted using Moola et al's guidelines. A search string was developed and run in May 2024 across three databases: MEDLINE (via PubMed), CINAHL via EBSCOhost, and Scopus. After duplicate removal, title, and abstract screening, full-text screening was performed, and peer-reviewed articles considering voice quality measures in Spanish-English bilingual speakers were included. Data were extracted and presented in table format, and the quality of the articles was assessed using the Checklist for Analytical Cross-Sectional Studies.

In total, 685 records were retrieved, with 485 remaining after duplicate removal. After title and abstract screening, 25 full texts were screened, including 8 articles in the review. Five studies included acoustic measures describing voice quality, with only three including auditory-perceptual analysis. The most commonly considered vocal trait in Spanish-English bilinguals was vocal fry, with the included studies pointing to increased vocal fry use when speaking English.

Only a few articles discuss potential vocal changes in Spanish-English bilinguals. Further research is needed to elucidate any potential vocal changes related to being a bilingual speaker, as the current small number of studies and mixed findings make drawing conclusions difficult. More standardization across voice and language assessment could be beneficial.