The perception of phonologically significant contrasts using speech envelope cues

The observation that many cochlear implantees demonstrate high levels of speech recognition, despite limited or distorted spectral information, has motivated research on the importance of temporal information for the perception of speech. The purpose of this study was to measure the recognition of speech contrasts via only the speech envelope before and after training. Test stimuli consisted of eight segmental and two suprasegmental contrasts of the Hebrew Speech Pattern Contrast test using a binary forced-choice paradigm. Multiplying the speech waveform with white noise eliminated spectral information. Results show that stress, intonation and manner of articulation were very well perceived using only temporal information, whereas voicing and place of articulation were perceived above chance levels. Results also show that vowels were more susceptible to the removal of spectral information than consonants. These findings help to better understand speech perception performance of hearing-impaired individuals, including cochlear implant users. They may also have practical implications for aural rehabilitation and sensory aids design for the Hebrew speaking population.