Do Voice Acoustic Parameters Differ Between Bilingual English-Spanish Speakers and Monolingual English Speakers During English Productions?

Background: In addition to language differences in fundamental frequency between bilinguals and monolinguals, studies have also included other acoustic parameters to analyze differences in voice production associated with the language spoken. Aim: To identify differences in voice acoustic parameters during English productions between monolingual and bilingual English speakers. Method: Exploratory cross-sectional study with two groups of subjects: monolingual English speakers (n = 40), and bilingual English-Spanish speakers (n = 13). Participants filled out a questionnaire and recorded one reading in English (second sentence of Rainbow passage “The rainbow is a division of white light into many beautiful colors”) under a “virtual-simulated” acoustic condition of No Noise and Medium Reverberation Time (0.8 seconds). Result: Analysis by gender shows that monolingual speakers had higher fundamental frequency mode, and lower standard deviation of fundamental frequency compared to bilingual English-Spanish speakers. Bilingual male speakers had higher jitter and harmonics-to-noise ratio than monolingual speakers. On the contrary, female bilingual speakers had lower jitter and shimmer than monolingual speakers. Conclusions: Speaking a second language may influence voice acoustic parameters, and therefore, should be considered when comparing acoustic speech metrics.