Graeme Clark Collection

Permanent URI for this collection

Search Results

Now showing 1 - 3 of 3
  • Item
    Thumbnail Image
    Research in auditory training
    Blamey, Peter J. ; Alcantara, Joseph I. (Academy of Rehabilitative Audiology, 1994)
    Speech perception and communication can improve as a result of experience, and auditory training is one way of providing experiences that may be beneficial. One of the most important factors influencing the effectiveness of auditory training is the amount of experience the client already has. Other factors include the severity of the hearing loss, the sensory device used, the environment, personal qualities of the client and clinician, the type of training, and the type of evaluation used. Despite a long history of clinical practice, the effects of these factors have been investigated in few controlled studies. Even in special cases where training has an obvious role, such as adults using cochlear implants, there has been little objective comparison of alternative training methods. One reason for this is the difficulty of carrying out definitive experiments that measure changes in performance over time in the presence of many confounding variables. These variables may also help to explain the apparently contradictory results that can be found in the literature on auditory training and in the diverse points of view expressed by practicing clinicians. Issues and methods appropriate for research in auditory training among adult clients are discussed with reference to the needs of modem clinical practice.
  • Item
    Thumbnail Image
    Formant-based processing for hearing aids
    Blamey, P. J. ; Dooley, G. J. ; Seligman, P. M. ; Alcantara, J. I. ; Gerin, E. S. ( 1994)
    A body-worn hearing aid has been developed with the ability to estimate formant frequencies and amplitudes in real time. These parameters can be used to enhance the output signal by "sharpening" the formant peaks, by "mapping" the amplitudes of the formants onto the available dynamic range of hearing at each frequency, or by resynthesizing a speech signal that is suited to the listener�s hearing characteristics. Initial evaluations have indicated small improvements in speech perception for three groups of subjects: users of a combined cochlear implant and speech processing hearing aid, normally hearing listeners in background noise, and a hearing aid user with a severe hearing loss.
  • Item
    Thumbnail Image
    Partial hearing loss in the macaque following the co-administration of kanamycin and ethacrynic acid
    Shepherd, R. K. ; Xu, S. A. ; Clark, Graeme M. ( 1994)
    Co-administration of kanamycin (KA) with the loop diuretic ethacrynic acid (EA) rapidly produces a profound hearing loss in the cat while maintaining normal renal function [Xu et al., Hear. Res. 70, 205-215 (1993)]. In the present paper we have applied this deafening procedure to the old world monkey Macaca fascicularis (macaque). Following the co-administration of KA and EA, the hearing loss in the macaque developed far slower than we observed in the cat. Moreover, unlike the cat, there was evidence of a partial recovery in the animal’s hearing, resulting in a bilaterally symmetrical high frequency hearing loss. The extent of this hearing loss was dependent on the dose of the EA administered. Finally, the most unexpected result of the present study was the degree of acute nephrotoxicity experienced by these animals following the drug administration. The sensitivity of this species to renal failure restricted the dose of EA that could be safely administered. In conclusion, the co-administration of KA and EA cannot reliably produce a profound hearing loss in the macaque. While it can produce a dose dependent high frequency hearing loss the animal will also experience acute renal failure that requires careful management.