A variety of approaches have been considered to improve speech recognition by cochlear implant subjects over the last 20 years. One approach involves using experimental data that probes the status of a particular subjects'electrically stimulated auditory system to tune conventional speech processing systems. Another approach involves investigating new speech processing approaches and algorithms. The goal of the proposed research is to link these two successful research methodologies by investigating the feasibility and optimization of novel speech processing techniques by specifically tuning the algorithm to the measured psychophysical parameters associated with a particular implant subject. The hypothesis that will be investigated is whether encoding dynamic changes in the frequency information present in speech by specifically encoding this information in a variable electrical pulse rate can improve speech understanding by cochlear implant subjects. In the first Specific Aim, a finite set of pulse rates, each based on psychophysical data collected from the subject being tested, will be used to code speech information in each electrode channel. This differs from traditional speech processing techniques which use a non-tuned fixed pulse rate in each channel, and differs from recently presented speech processing strategies in that a discrete number of rates, as opposed to a continuum, are utilized. The second Specific Aim will consider the utility of coding speech in virtual channels, where each virtual channel is defined by an electrode and a stimulation rate.
Both Aims will be addressed by testing the proposed speech processing algorithms after adjusting the parameters of the algorithms based on measured psychophysical data. In the United States alone, there are 28 million individuals with hearing loss, and 1-2 million completely deaf individuals. As a result of increasing levels of noise in the modern environment, hearing loss ocurs earlier in life and progresses more rapidly, suggesting that these numbers will continue to grow. The goal of this research is to provide improved speech recognition performance for such individuals by optimizing novel techniques for processing and coding speech information.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC007994-04
Application #
7546996
Study Section
Special Emphasis Panel (ZDC1-SRB-W (48))
Program Officer
Miller, Roger
Project Start
2006-01-01
Project End
2010-12-31
Budget Start
2009-01-01
Budget End
2009-12-31
Support Year
4
Fiscal Year
2009
Total Cost
$221,386
Indirect Cost
Name
Duke University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Desmond, Jill M; Collins, Leslie M; Throckmorton, Chandra S (2013) Using channel-specific statistical models to detect reverberation in cochlear implant stimuli. J Acoust Soc Am 134:1112-20
Duran, Sara I; Collins, Leslie M; Throckmorton, Chandra S (2012) Stream segregation on a single electrode as a function of pulse rate in cochlear implant listeners. J Acoust Soc Am 132:3849-55
Stohl, Joshua S; Throckmorton, Chandra S; Collins, Leslie M (2009) Investigating the effects of stimulus duration and context on pitch perception by cochlear implant users. J Acoust Soc Am 126:318-26
Morton, Kenneth D; Torrione Jr, Peter A; Throckmorton, Chandra S et al. (2008) Mandarin Chinese tone identification in cochlear implants: predictions from acoustic models. Hear Res 244:66-76
Stohl, Joshua S; Throckmorton, Chandra S; Collins, Leslie M (2008) Assessing the pitch structure associated with multiple rates and places for cochlear implant users. J Acoust Soc Am 123:1043-53
Remus, Jeremiah J; Collins, Leslie M (2008) Comparison of adaptive psychometric procedures motivated by the theory of optimal experiments: simulated and experimental results. J Acoust Soc Am 123:315-26
Throckmorton, Chandra S; Selin Kucukoglu, M; Remus, Jeremiah J et al. (2007) The effect of frequency estimation on speech recognition using an acoustic model of a cochlear implant. Hear Res 228:230-1
Remus, Jeremiah J; Throckmorton, Chandra S; Collins, Leslie M (2007) Expediting the identification of impaired channels in cochlear implants via analysis of speech-based confusion matrices. IEEE Trans Biomed Eng 54:2193-204
Remus, Jeremiah J; Collins, Leslie M (2007) A comparison of adaptive psychometric procedures based on the theory of optimal experiments and bayesian techniques: implications for cochlear implant testing. Percept Psychophys 69:311-23
Throckmorton, Chandra S; Selin Kucukoglu, M; Remus, Jeremiah J et al. (2006) Acoustic model investigation of a multiple carrier frequency algorithm for encoding fine frequency structure: implications for cochlear implants. Hear Res 218:30-42