The effect of background noise on speech perception in monolingual and bilingual adults with normal hearing

BACKGROUND: Previous studies have highlighted that bilingual listeners have a deficit in speech perception in their second language compared with monolingual listeners in noisy listening environments. This deficit may give rise to educational and occupational implications for bilingual speakers who are studying or working in non-native language environments in poor acoustic conditions. OBJECTIVES: To compare the speech perception performance of monolingual English speakers and English as a second language (ESL) bilinguals within environments with various levels of background noise and to examine whether bilinguals with an early age of second language acquisition would perform better than those with a late age of acquisition. STUDY SAMPLE: Two groups of adult listeners with normal hearing participated: monolingual British English listeners (N = 15) and bilingual Arabic listeners for whom English was their second language and who were proficient in English (N = 15). The quick speech-in-noise (QuickSIN) test was used to assess signal-to-noise ratio (SNR) loss and SNR-50 for both groups. RESULTS: The QuickSIN test results indicated that bilingual Arabic listeners with normal hearing displayed a mild SNR loss comparable to that observed for a person with hearing loss, indicating a higher SNR needed for this population to achieve a comparable level of comprehension to their monolingual English peers. CONCLUSION: Results highlight the importance of measuring SNR loss to obtain accurate diagnosis and potential rehabilitative information that is not available from audiogram studies.