The long term objective of the proposed research is to improve the speech performance of current signal processing strategies for cochlear prosthesis. The present study will propose a series of strategies which will stimulate the electrodes using information that is """"""""closest"""""""", perceptually, to the input signal. In these strategies, the channel amplitudes are selected such that the difference between the stimulating (electrical) pattern and the acoustic pattern is minimized, that is, channel amplitudes are selected by optimizing a perceptually motivated error criterion. Two types of error criteria will be investigated, a temporal criterion, which emphasizes the importance of envelope information, and a spectral criterion which emphasizes the importance of spectral information. The proposed experiments have three specific aims.
The first aim i s to investigate whether a strategy designed for better spectral matching performs better on speech recognition tasks than the conventional Continuous Interleaved Sampling (CIS) strategy.
The second aim i s to understand the importance of spectral information on word recognition with the Med-El and Nucleus cochlear implant devices. To accomplish this aim, we will present to implant patients sentences from the TIMIT speech corpus in which the vowels or the consonants will be replaced with white noise.
The third aim i s to investigate whether a strategy designed for better waveform matching performs better on speech recognition tasks than the CIS strategy. The proposed strategies will be implemented on a portable speech processor and will be tested with cochlear implant patients. The results of these investigations will lay the groundwork for a better understanding of which information, temporal (envelope) or spectral, is perceptually more important for cochlear implants. Most importantly, it will open new avenues for the development of future signal processing strategies for cochlear prosthesis.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
1R01DC003421-01A2
Application #
2860774
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Project Start
1999-05-01
Project End
1999-07-31
Budget Start
1999-05-01
Budget End
1999-07-31
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Arkansas at Little Rock
Department
Miscellaneous
Type
Schools of Arts and Sciences
DUNS #
City
Little Rock
State
AR
Country
United States
Zip Code
72204
Li, Ning; Loizou, Philipos C (2008) Factors influencing intelligibility of ideal binary-masked speech: implications for noise reduction. J Acoust Soc Am 123:1673-82
Li, Ning; Loizou, Philipos C (2008) A glimpsing account for the benefit of simulated combined acoustic and electric hearing. J Acoust Soc Am 123:2287-94
Li, Ning; Loizou, Philipos C (2008) Effect of spectral resolution on the intelligibility of ideal binary masked speech. J Acoust Soc Am 123:EL59-64
Li, Ning; Loizou, Philipos C (2007) Factors influencing glimpsing of speech in noise. J Acoust Soc Am 122:1165-72
Stickney, Ginger S; Loizou, Philipos C; Mishra, Lakshmi N et al. (2006) Effects of electrode design and configuration on channel interactions. Hear Res 211:33-45
Loizou, Philipos C; Lobo, Arthur; Hu, Yi (2005) Subspace algorithms for noise reduction in cochlear implants. J Acoust Soc Am 118:2791-3
Parikh, Gaurang; Loizou, Philipos C (2005) The influence of noise on vowel and consonant cues. J Acoust Soc Am 118:3874-88
Loizou, Philipos C; Mani, Arunvijay; Dorman, Michael F (2003) Dichotic speech recognition in noise using reduced spectral cues. J Acoust Soc Am 114:475-83
Loizou, Philipos C; Stickney, Ginger; Mishra, Lakshmi et al. (2003) Comparison of speech processing strategies used in the Clarion implant processor. Ear Hear 24:12-9
Qian, Haifeng; Loizou, Philipos C; Dorman, Michael F (2003) A phone-assistive device based on Bluetooth technology for cochlear implant users. IEEE Trans Neural Syst Rehabil Eng 11:282-7

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