Bilingualism and speech recognition in silence and noise in adults

To compare the ability to recognize sentences in silence and in noise in monolingual normal-hearing Brazilian Portuguese speakers, and bilingual speakers of Brazilian Portuguese and German, and bilingual speakers of Brazilian Portuguese and Italian, as well as to analyze the influence of age of second language acquisition on the performance of bilinguals.

87 normal-hearing individuals aged between 18 and 55 years participated of this research. They were categorized into: Control Group, composed by 30 monolingual Brazilian Portuguese speakers; German Research Group, 31 simultaneous bilingual native speakers of Portuguese and speakers of German as a second language and; Italian Research Group, consisting of 26 successive bilinguals, native speakers of Portuguese and speakers of Italian as a second language. The Sentence List Test in Brazilian Portuguese was used to measure their Sentence Recognition Thresholds in Silence and Noise.

In silence, there were no statistically significant differences in performance when comparing the bilingual to the monolingual individuals, and when comparing the bilingual speakers among themselves. On the other hand, in noise, there was a significant difference between the bilingual groups and the monolingual one. However, there were no significant differences between the bilingual groups when their performance was compared.

Bilingualism positively influenced the development of language and listening skills, which led the bilinguals to outperform in speech recognition in the presence of noise. Also, the period of a second language acquisition did not influence bilingual performance.