Spectral integration of English speech for non-native English speakers.

When listening in noisy environments, good speech perception often relies on the ability to integrate cues distributed across disparate frequency regions. The present study evaluated this ability in non-native speakers of English. Native English-speaking and native Mandarin-speaking listeners who acquired English as their second language participated. English sentence recognition was evaluated in a two-stage procedure. First, the bandwidth associated with ∼15% correct was determined for a band centered on 500 Hz and a band centered at 2500 Hz. Performance was then evaluated for each band alone and both bands combined. Data indicated that non-natives needed significantly wider bandwidths than natives to achieve comparable performance with just the low or just the high band alone. Further, even when provided with wider bandwidth within each frequency region, non-natives were worse than natives at integrating information across bands. These data support the idea that greater bandwidth requirements and a reduced ability to integrate speech cues distributed across frequency may play an important role in the greater difficulty non-natives often experience when listening to English speech in noisy environments.