Table of Contents
ISRN Signal Processing
Volume 2012, Article ID 628706, 6 pages
Research Article

Cochlear Implant Speech Processing Using Wavelet Transform

1Medical Physics & Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran 1417613151, Iran
2Biomedical Group, Research Centre for Science and Technology in Medicine, Tehran 14185615, Iran
3Department of Electrical and Computer Engineering, Ryerson University, Toronto, ON, Canada M5B 2K3
4Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1

Received 9 April 2012; Accepted 29 May 2012

Academic Editors: W.-L. Hwang, S. Kwong, and A. Rubio Ayuso

Copyright © 2012 M. Mehrzad et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We present a method for coding speech signals for the simulation of a cochlear implant. The method is based on a wavelet packet decomposition strategy. We used wavelet packet db4 for 7 levels, generated a series of channels with bandwidths exactly the same as nucleus device, and applied an input stimulus to each channel. The processed signal was then reconstructed and compared to the original signal, which preserved the contents to a high percentage. Finally, performance of the wavelet packet decomposition in terms of computational complexity was compared to other commonly used strategies in cochlear implants. The results showed the power of this method in processing of the input signal for implant users with less complexity than other methods, while maintaining the contents of the input signal to a very good extent.