Sounds heard through a cochlear implant do not perceived the same as sound heard with normal hearing. Cochlear implant listeners who have previously had normal hearing often describe the sound as being robotic or like the sound of an off-tuned radio.  Words can be made out and over time the brain adjusts to the new signals; what is heard becomes more natural.  One of the goals of our lab is to determine how different regions of the brain change as cochlear implant listenersget more experience.

We can’t know exactly what the world sounds like to someone using a cochlear implant, and it will vary between people, but some of the research in our lab involves processing sounds to simulate the processing that is done by a cochlear implant.  This helps us get a better understanding of how listeners with normal hearing use the cues that are in speech to determine what word is being said, whether the speaker is a male or female, and what emotion is being expressed.  Are they angry or sad for example, or do they sound anxious?  We can use this information to improve the information that is transmitted by a cochlear implant.

Speech understanding

Below are some sounds that we use in our studies, which have been processed using an 8-channel noise vocoder to simulate cochlear implant processing.  The vocoded sounds are on the left and the original sounds are on the right.