Speech production skills in adults with cochlear implants

To assess the effects of a somatosensory perturbation and an auditory perturbation on sibilant contrasts in normal hearing speakers and post-lingually deaf adults with a cochlear implant (CI). We tested the hypothesis that long-term auditory deprivation experienced by the CI speakers would reduce their ability to adapt to the perturbations. Method: Three normal hearing speakers and one CI speaker participated. Somatosensory feedback during speech was altered by a built-up electropalate that modified the shape of the anterior palate and contrasted with a typical electropalate. Auditory feedback was altered by delivering masking noise to the control speakers and turning OFF the CI speaker's implant. Results: The articulatory and acoustic distinction between /s/ and /S/ was compromised by the perturbed electropalate in all speakers but the CI speaker was most impaired by the perturbation. The /s-S/ distinction improved with the normal electropalate but mostly for the control speakers. Conclusion: The distinction between the fricatives /s/ and /S/ was reduced by altering the shape of the anterior palate. The distinction was especially compromised in a post-lingually deaf CI user suggesting that long-term auditory deprivation may interfere with speech sensorimotor adaptation despite prosthetic hearing. Testing with other CI users is in progress.