The use of multiple channel cochlear prostheses to improve the communication abilities of profound/totally deaf patients is now an established procedure. Design improvements for these prostheses have been undertaken in the University of Melbourne's Department of Otolaryngology since 1970. The long term goal of the program is to achieve good speech discrimination without lip reading for a wide range of patients including children. The four specific aims of this grant proposal are as follows: (1) The first aim is to conduct psychophysical studies on profound/totally deaf patients who will be implanted with the receiver-stimulator, CI2, in the middle of 1987. CI2 is being developed under NIH Grant NS21027 (""""""""An advanced multi-channel cochlear implant for deafness""""""""; completion date: August 1987). It will produce simultaneous stimulation on three bipolar electrode pairs within a stimulus period (inverse of repetition rate). (2) The second aim is to monitor the changes in electrode impedance in patients following implantation by the telemetry system incorporated in the electronic design of CI2. (3) The third aim of this grant proposal is to develop a new receiver-stimulator, CI3, to enable research into the nature of the hearing sensations produced by electrical stimulation using different pulse rates on different electrode pairs, or alternatively the same rate on a large number (greater than three) of electrode pairs. CI2 and the existing receiver-stimulator, CI1, are not suitable for this research. (4) The fourth aim of this proposal is to undertake psychophysical studies on patients with CI3. The results of the psychophysical studies mentioned in (1) and (4) above will be used to direct the choice of the detailed structure and parameter values of the algorithms to be used in the speech processors for patients who will be implanted with CI2 or CI3. Loudness summation, electrode identification, repetition rate identification and synthetic vowel studies will be conducted. The development of the receiver-stimulator, CI3, will involve the design and layout of a single LSI CMOS integrated circuit to be fabricated under contract to VLSI Technology Ltd., Ca. The integrated circuit will be packaged into an implantable receiver- stimulator under contract to Cochlear Pty. Limited, Sydney.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC001282-09
Application #
2126391
Study Section
Hearing Research Study Section (HAR)
Project Start
1991-04-01
Project End
1994-03-31
Budget Start
1993-04-01
Budget End
1994-03-31
Support Year
9
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Melbourne
Department
Type
DUNS #
City
Melbourne
State
Country
Australia
Zip Code
3010
Richardson, L M; Busby, P A; Blamey, P J et al. (1998) Studies of prosody perception by cochlear implant patients. Audiology 37:231-45
McDermott, H J; McKay, C M (1996) Loudness ratio production by cochlear implantees using the spectral maxima sound processor. Scand Audiol 25:83-90
Cohen, L T; Busby, P A; Whitford, L A et al. (1996) Cochlear implant place psychophysics 1. Pitch estimation with deeply inserted electrodes. Audiol Neurootol 1:265-77
Cohen, L T; Busby, P A; Clark, G M (1996) Cochlear implant place psychophysics. 2. Comparison of forward masking and pitch estimation data. Audiol Neurootol 1:278-92
McDermott, H J; McKay, C M (1994) Pitch ranking with nonsimultaneous dual-electrode electrical stimulation of the cochlea. J Acoust Soc Am 96:155-62
McKay, C M; McDermott, H J; Clark, G M (1994) Pitch percepts associated with amplitude-modulated current pulse trains in cochlear implantees. J Acoust Soc Am 96:2664-73