Perception of vowels and prosody by cochlear implant recipients in noise

The aim of the present study was to compare the ability of cochlear implant (CI) recipients to recognise speech prosody in the presence of speech-weighted noise to their ability to recognise vowels in the same test paradigm and listening condition. All test materials were recorded from four different speakers (two male, two female). Two prosody recognition tasks were developed, both using single words as stimuli. The first task involved a question/statement distinction, while the second task required listeners to make a judgement about the speaker's attitude. Vowel recognition tests were conducted using vowel pairs selected on the basis of specific acoustic cues (frequencies of the first two formants and duration). Ten CI users and ten normal-hearing controls were tested in both quiet and an adaptive noise condition, using a two-alternative forced-choice test paradigm for all the tests. Results indicated that vowel recognition was significantly better than prosody recognition in both listener groups in both quiet and noise, and that question/statement discrimination was the most difficult task for CI listeners in noise. Data from acoustic analyses were used to interpret differences in performance on different tasks and with different speakers.

As a result of this activity, readers will be able to (1) describe suitable methods for comparing vowel and prosody perception in noise, (2) compare performance on vowel and prosody perception tasks in quiet in normal-hearing listeners and cochlear implant recipients, (3) compare performance on vowel and prosody perception tasks in noise in normal-hearing listeners and cochlear implant recipients and (4) relate performance on prosody tasks in quiet to performance on these tasks in noise.