16-11-2010, 03:56 PM
This article describes about wavelet packet (WP) filterbank.Most effective means of improving the auditory receptive abilities of people with profound hearing loss is cochlear implants(CI).Current cochlear implants consist of a microphone, a speech processor, a transmitter, a receiver and an electrode array which is positioned inside the cochlea.For decomposintion of input audio signal into different frequency bands and delivering the most appropriate stimulation pattern to the electrodes,speech processors are used.The bandwidths of the frequency bands are approximately equal to the critical bands, where low- frequency bands have higherfrequency resolution than high- frequency bands.Over the past two decades,most of the discoveries were based on mimicing firing patters inside the cochlea as naturally as possible.“NofM” strategies such as Advanced Combinational Encoder (ACE) , separate speech signals into M sub-bands and derive envelope information from each band signal. N bands with the largest amplitude are then selected for stimulation.
Studies revealed that, there are two basic cues for pitch perception in cochlear implant recipients.The first cue, known as temporal pitch, is related to the temporal fluctuations in the envelopes of each spectral band. The second cue, known as place pitch, is related to the location of excitation along the cochlea.
Get the report pdf at:
http://www.mediafire?8xpvc78z5jmssaq
Studies revealed that, there are two basic cues for pitch perception in cochlear implant recipients.The first cue, known as temporal pitch, is related to the temporal fluctuations in the envelopes of each spectral band. The second cue, known as place pitch, is related to the location of excitation along the cochlea.
Get the report pdf at:
http://www.mediafire?8xpvc78z5jmssaq