The Intelligibility of Time-Compressed Speech Is Correlated with the Ability to Listen in Modulated Noise.

Abstract

Speech perception in difficult listening conditions depends highly on the temporal processing ability of the auditory pathway. In the present study, we investigate the inter-subject variability of young normal-hearing listeners in the identification of time-compressed speech and how the ability to identify time-compressed speech, as assessed by the speech reception threshold (SRTrate: the speech rate at which 50% of the speech is perceived correctly) is associated with the ability to identify speech in unmodulated (SRTunmod) and modulated noise (SRTmod). These tasks are highly dependent on the temporal processing abilities of the auditory pathway. We observed a large inter-subject variability in the SRTrate and found that it is significantly correlated with the SRT when listening to unmodulated and modulated noise. Furthermore, we found that listeners who are better at perceiving speech at high rates are better in listening to speech in modulated noise. This effect persisted even when controlling for their ability to perceive speech in unmodulated noise. In addition, we also found that an increase in speech rate from 2.7 to 6.6 syllables per second resulted in a reduction in glimpsing of 5.3dB when listening to speech in a 4-Hz amplitude-modulated masker, even though speech in quiet was 100% intelligible at both rates. These results indicate that the ability of young normal-hearing individuals to efficiently process temporal features of speech is an imperative factor when listening to speech in difficult listening situations.