Harmonic coherent demodulation for improving sound coding in cochlear implants

The paper presents a promising application of the coherent demodulation technique to improving hearing with cochlear implants. It has been a challenge to encode temporal fine structure (TFS) in cochlear implants for better speech and music perception. We propose a pitch-synchronized coherent demodulation strategy-Harmonic Single Sideband Encoder (HSSE)-to efficiently encode TFS cues. A dynamic carrier estimation approach based on harmonic detection was chosen to enhance temporal pitch coding in cochlear implants. Acoustic analysis results showed that the HSSE strategy preserves temporal fine structure cues including fundamental frequency (F0) information as well. The coding of temporal fine structure cues in cochlear implants could be potentially improved with the F0-synchronized coherent demodulation.