Comparison between a measure based on mutual information and frequency importance functions for consonant recognition

In this work, we seek to find how the information about consonant recognition pertaining to the various phonemes is distributed in frequency. For this task, we used the mutual information between phonetic labels and spectral energy. The analysis was performed in the perspective of cochlear implants and how information is distributed among the various channels of the cochlear implant. The calculation of mutual information was performed for each of the six channels. The computed values of mutual information between phonetic labels and spectral energy were relatively high for channels 4, 5 and 6. This indicates that those high frequency channels contain relatively high amount of information about phonetic classification for consonant stimuli and is consistent with the existing results from the intelligibility tests. Remarkable correspondence between the mutual information values of individual channels for consonant stimuli and the frequency importance functions for consonant recognition was observed.