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Listen and understand
Everyone knows it: you meet with friends in a restaurant and despite the conversations of other guests, it is easy to understand each other. What is natural for people with normal hearing is a major problem for people with a cochlear implant (CI). Cochlear implants restore hearing to deaf people through direct stimulation of the auditory nerve. While speech comprehension works well in quiet situations, considerable background noise makes it impossible for CI wearers to understand the person they are talking to.
In such situations, binaural signal processing strategies (BSS) can improve speech understanding. BSS use auditory information from the CIs exchanged between both ears. For aesthetic reasons, only a wireless connection can be used. However, since cochlear implants use batteries for power supply, the energy available for the necessary data exchange is severely limited. In addition, it is necessary to transmit the data with as little delay as possible so that no echo effects occur and the BSS can be used efficiently.
In order to solve the problem of low latency and low bit rate of information exchange between CIs, scientists at the L3S are researching a signal compression system that – unlike conventional compression methods – does not use the input signal of the cochlear implants, but instead uses the excitation patterns of the CIs, which contain the essential information of the auditory impression in a compact form.
The methods developed will be tested on CI users together with the German Hearing Centre in Hanover and will in future be used in conjunction with a BSS developed there under the direction of Prof. Dr-Ing. Waldo Nogueira.
Reemt Hinrichs is a research assistant at L3S and at the Institute of Information Processing. He deals with data compression and its applications in the field of biosignal processing.