A recursive wavelet-based strategy for real-time cochlear implant speech processing on PDA platforms.

This paper presents a wavelet-based speech coding strategy for cochlear implants. In addition, it describes the real-time implementation of this strategy on a personal digital assistant (PDA) platform. Three wavelet packet decomposition tree structures are considered and their performance in terms of computational complexity, spectral leakage, fixed-point accuracy, and real-time processing are compared to other commonly used strategies in cochlear implants. A real-time mechanism is introduced for updating the wavelet coefficients recursively. It is shown that the proposed strategy achieves higher analysis rates than the existing strategies while being able to run in real time on a PDA platform. In addition, it is shown that this strategy leads to a lower amount of spectral leakage. The PDA implementation is made interactive to allow users to easily manipulate the parameters involved and study their effects.