Performance of the Piecewise Rate Modulation Strategy to Convey Mandarin Tonal Information for Cochlear Implant Using Neural Network Simulation

In order to improve the pitch perception of cochlear implant (CI) users speaking tonal language, it has been suggested to frequency-modulate the electric stimulus rate by the spectral information of the tonal language. A piecewise CI rate modulation strategy has been recently proposed, which not only encoded the spectral information but also took account of the psychological perception feature for the stimulus rate variation by CI users. This paper further examines its performance to convey Mandarin tonal information by a neural-network-based simulation. The experimental results shown that the correct rates to identify the four Mandarin tones of 80 Mandarin monosyllabic words were 95%, 95%, 100% and 100%, respectively, indicating that the piecewise rate modulation strategy might efficiently convey Mandarin tonal information. Therefore, the piecewise rate modulation strategy could help to design novel CI electric stimulator and enhance the speech perception ability of CI users speaking tonal language, such as Mandarin.