Speech perception in noise by young sequential bilingual children

The objective of this study was to ascertain the effects of competitive noise on second language perception skills of sequentially bilingual children and to compare the results with those relating to matched monolingual peers. Fifteen bilingual immigrant children (aged 6-10 years) (BL) learning through their second language (L2), which was Italian, were matched with 15 peers who only spoke Italian (IO). All immigrant children had arrived in Italy and were exposed to L2 after their 4th year of life. The speech-to-noise ratio (SNR) needed to obtain 50% intelligibility – the speech reception threshold (SRT) – for Italian words was measured against the Italian version of ICRA noise, using an adaptive method. Moreover, presentation of phrases against a contralateral continuous discourse (informational masking) was carried out to exclude possible biases due to differences in memory, attention, or other central auditory processing disorders between groups. The SNR was -2.7 dB (SD 1.7; range: -5.5 to + 0.9) for the BL group and -5.3 dB (SD 2.3; range: -8.8 to -0.9) for the IO group (p < 0.01). With contralateral continuous discourse presentation the SNR were -32.8 dB (SD 2.4; range: -36.1 to -28.2) for the BL group and -27.8 dB (SD 2.1; range: -31.7 to -24.1) for the OI group (p < 0.01). Even sequential bilingual individuals exposed to L2 at 4 years old had worse speech perception in noise than their matched IO peers. On the other hand, the BL group demonstrated superior divided attention skills in tests with competitive contralateral discourse (p < 0.01).