Top-Down Restoration of Speech in Cochlear-Implant Users.

Top-Down Restoration of Speech in Cochlear-Implant Users. Hear Res. 2013 Dec 21; Authors: Bhargava P, Gaudrain E, Başkent D Abstract In noisy listening conditions, intelligibility of degraded speech can be enhanced by top-down restoration. Cochlear implant (CI) users have difficulty understanding speech in noisy environments. This could partially be due to reduced top-down restoration of speech, caused by the changes that the electrical stimulation imposes on the bottom-up cues. We tested this hypothesis using the phonemic restoration (PhR) paradigm in which speech interrupted with periodic silent intervals is perceived illusorily continuous (continuity illusion or CoI) and becomes more intelligible (PhR benefit) when the interruptions are filled with noise bursts. Using meaningful sentences, both CoI and PhR benefit were measured in CI users, and compared with those of normal-hearing (NH) listeners presented with normal speech and 8-channel noise-band vocoded speech, simulating CIs. CI users showed different patterns in both PhR benefit and CoI, compared to NH results with or without the CI simulation. However, they were able to use top-down restoration under certain test conditions. This observation supports the idea that changes in bottom-up cues can impose changes to the top-down processes needed to enhance intelligibility of degraded speech. The knowledge that CI users seem to be able to do restoration under the right circumstances could...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research