Cochlear implants are widely accepted as the unique and most effective ways for individuals with severe to profound hearing loss to restore some degree of hearing. Speech coding strategies play an extremely important role in optimizing the cochlear implant user‟s communicative potential. Various speech coding strategies have been developed in the past fifty years to simulate the peripheral auditory system as naturally as possible. Most of the strategies are used to mimic the human cochlea‟s spatial encoding pattern, which stimulates auditory fibers at given frequencies based on the frequency characterizations of speech. However, these strategies cannot simulate the human cochlea‟s temporal encoding pattern well. Also, current spreading as well as channel interactions are major problems. This paper presents a new solution, which generates stimulating pulsatile series at zero-crossings in the domain of wavelet transform, called wavelet zero-crossings stimulation (WZCS). With amplitude modulation and phase information (zero-crossings) encoded, the WZCS is aimed at improving the recognition of tonal language speech and speech in multi-talker backgrounds. WZCS, frequency amplitude modulation encoding (FAME) and continuous interleaved sampling (CIS) were compared by computer simulation, and hearing test experiment results showed that the recognition of speech synthesized through WZCS was better in both quiet and noisy environment than CIS strategy. Results of the experiment also showed significant improvement with WZCS over FAME on tone
recognition, both in quiet and noisy conditions. Further study demonstrated that WZCS could keep the temporal cues (or phase information), and some fine structure of speech remained in the stimulating pulsatile series. Most important is that the correlations of original sounds were found to be obviously higher than in signals reconstituted through CIS and FAME strategies. Thus, the application of WZCS strategy to cochlear implants may be a significant improvement.