The purpose of this study was to examine the effects of altering the fundamental frequency (F0) on perception of prosody and speaker gender in both normal-hearing listeners and cochlear implant (CI) recipients. Tests with natural speech and defined modifications of the F0 were performed, and the resulting changes in perception were measured. Compared to the normal-hearing listeners, most of the CI users exhibited worse outcomes, especially for sentence stress. In contrast, the speaker gender tests yielded similar results for both groups when artificially modifying the F0 contour. The results seemed to be strongly related to the duration of alterations in F0. Although the perception of prosodic cues was limited in most of the CI recipients, they showed qualitatively similar results to normal-hearing listeners in that the boundary between questions and statements and between female and male voices was comparable. A large inter-individual difference in performance was observed among the CI recipients, which could not be attributed to different processor or implant types or to other factors such as implant experience.

The outcome emphasizes the importance of both F0 and intensity for CI users' identification of sentence-based stress. Both cues were used separately for stress perception, but combining the cues provided extra benefit for most of the subjects.

Bimodal hearing improved overall speech recognition of both the target and the masker. No evidence for better target-masker separation with bimodal fitting could be found.

Noise interferers are not sufficient to reflect difficulties experienced with speech understanding in noise for bilateral and bimodal CI users.

The corruption of intonation contours has detrimental effects on sentence-based speech recognition in normal-hearing listeners Binns and Culling [(2007). J. Acoust. Soc. Am. 122, 1765–1776]. This paper examines whether this finding also applies to cochlear implant (CI) recipients. The subjects’ F0-discrimination and speech perception in the presence of noise were measured, using sentences with regular and inverted F0-contours. The results revealed that speech recognition for regular contours was significantly better than for inverted contours. This difference was related to the subjects’ F0-discrimination providing further evidence that the perception of intonation patterns is important for the CI-mediated speech recognition in noise.

Advances in speech coding strategies and electrode array designs for cochlear implants (CIs) predominantly aim at improving speech perception. Current efforts are also directed at transmitting appropriate cues of the fundamental frequency (F0) to the auditory nerve with respect to speech quality, prosody, and music perception. The aim of this study was to examine the effects of various electrode configurations and coding strategies on speech intonation identification, speaker gender identification, and music quality rating. In six MED-EL CI users electrodes were selectively deactivated in order to simulate different insertion depths and inter-electrode distances when using the high definition continuous interleaved sampling (HDCIS) and fine structure processing (FSP) speech coding strategies. Identification of intonation and speaker gender was determined and music quality rating was assessed. For intonation identification HDCIS was robust against the different electrode configurations, whereas fine structure processing showed significantly worse results when a short electrode depth was simulated. In contrast, speaker gender recognition was not affected by electrode configuration or speech coding strategy. Music quality rating was sensitive to electrode configuration. In conclusion, the three experiments revealed different outcomes, even though they all addressed the reception of F0 cues. Rapid changes in F0, as seen with intonation, were the most sensitive to electrode configurations and coding strategies. In contrast, electrode configurations and coding strategies did not show large effects when F0 information was available over a longer time period, as seen with speaker gender. Music quality relies on additional spectral cues other than F0, and was poorest when a shallow insertion was simulated.

In complex listening situations elderly persons reveal worse speech understanding than younger subjects. Differences in speech perception can partly be attributed to cognitive abilities. In particular, working memory seems to be an important factor.

In CI recipients, IM cannot be reduced by means of differences in f0 between the competing talkers, but only by level differences. This might be explained by the restricted spectral resolution and the insufficient transmission of f0 in CIs. Adverse effects in NL can predominantly be attributed to IM, while additional masking effects take place in CI recipients.