Perception of acoustically degraded sentences in bilingual listeners who differ in age of english acquisition.

PURPOSE: The effects of acoustic degradation and context use on sentence perception were evaluated in listeners differing in age of English acquisition.
METHOD: Five groups of 8 listeners, native monolingual (NM), native bilingual (NB), and early, late, and very late non-native bilingual (NN-E, NN-L, and NN-VL, respectively), identified target words in 400 Speech-Perception-in-Noise (SPIN) sentences presented in 8 combinations of noise (+6 vs. 0 dB signal-to-noise ratio), reverberation (1.2 vs. 3.6 s reverberation time), and context (high vs. low predictability).
RESULTS: Separate effects of noise, reverberation, and context were largely level dependent and more significant than their interaction with listeners' age of English acquisition. However, the effect of noise, as well as the combined effect of reverberation and context, was mediated by age of acquisition. NN-VL listeners' performance was significantly compromised in all test conditions. NB, NN-E, and NN-L listeners' use of context, by contrast, deviated substantially from the monolingual normative in difficult listening conditions.
CONCLUSIONS: Findings suggest that linguistic background needs to be considered in the understanding of bilingual listeners' context use in acoustically degraded conditions. Direct comparison of early bilingual listeners' performance with monolingual norms may be inappropriate when speech is highly degraded.