Enhanced harmonics for music appreciation on cochlear implant

The temporal fine structure in music consists of harmonics which is important for music appreciation. The lack of this temporal fine structure in the most used cochlear implant encoding strategy, contributes their lack of the music appreciation. The purpose of this paper is to enhance the harmonics for music appreciation on cochlear implant user. In the first experiment we processed the prior music signal with voice coder (vocoder). During prior processing, the harmonics of original music was degraded. In the second experiment, we used well known signal enhancement, Frequency-Amplitude-Modulation-Encoding (FAME), to enhance the harmonics of prior music. Objective test was conducted to measure the quality of music relative to original music using log spectral distance (LSD). The music quality between the prior and after enhancement are 2,3 and 2,1, respectively. The higher value of LSD means that the enhanced music got worsens. We also conducted subjective listening test from two subjects, 10 musicians and 10 non-musicians, whose their music appreciation is decreasing after the music was enhanced by FAME. It reveals that FAME strategy is not useful to enhance harmonics in signal processing of cochlear implant.