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 childrenand to compare the results with those relating to matched monolingual peers. Fifteen bilingual immigrant children (aged 6-10 years) (BL) learningthrough their second language (L2), which was Italian, were matched with 15 peers who only spoke Italian (IO). All immigrant children had arrivedin 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 receptionthreshold (SRT) – for Italian words was measured against the Italian version of ICRA noise, using an adaptive method. Moreover, presentationof phrases against a contralateral continuous discourse (informational masking) was carried out to exclude possible biases due to differences inmemory, 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 BLgroup 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 sequentialbilingual 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 groupdemonstrated superior divided attention skills in tests with competitive contralateral discourse (p < 0.01).