Title page for ETD etd-03222007-190636

Document Type Master's Dissertation
Author Stroebel, Deidre
Email s85243435@tuks.co.za
URN etd-03222007-190636
Document Title The clinical value of the auditory steady state response for early diagnosis and amplification for infants (0-8 months) with hearing loss
Degree Master of Communication Pathology
Department Communication Pathology
Advisor Name Title
Dr de Wet Swanepoel
Ms E Groenewald
  • Objective tests
  • estimate behavioral thresholds
  • auditory brainstem response
  • ASSR measured thresholds
  • ASSR predicted thresholds
  • frequency specific
  • auditory evoked potentials.
  • test battery
  • validation of hearing aids
  • auditory steady state response
Date 2006-04-25
Availability unrestricted

There has always been a need for objective tests that assess auditory function in infants, young children, and/or any patient whose development level precludes the use of behavioral audiometric techniques. Although the Auditory Brainstem Response (ABR) is seen as the ‘gold standard’ in the field of objective audiometry, it presents with its own set of limitations. The Auditory Steady State Response (ASSR) has gained considerable attention and is seen as a promising addition to the AEP ‘family’ to address some of the limitations of the ABR. The ASSR promises to estimate all categories of hearing loss (mild to profound) in a frequency specific manner. It also indicates to the possibility to validate hearing aid fittings by determining functional gain of hearing aids by determining unaided and aided ASSR thresholds.

An exploratory research design was selected in order to compare unaided thresholds, obtained through the use of three different procedures – ABR, ASSR and behavioral thresholds. Aided thresholds were also obtained and compared with two procedures – the aided ASSR (measured and predicted) and aided behavioral threshold. The results indicated that both the ABR (tone burst and click) and ASSR provided a reasonable estimation of the subsequently obtained behavioral audiograms. The ASSR, however, approximated the behavioral thresholds closer than the ABR and were furthermore able to quantify hearing thresholds accurately for subjects with severe and profound hearing losses. The result indicated further that the ASSR can be instrumental in the validation process of hearing aid fittings in infants. These results demonstrated however, that the ASSR measured thresholds underestimate the aided behavioral thresholds and the aided ASSR predicted thresholds overestimate the aided behavioral thresholds.

The research concluded that the ASSR is useful in estimating frequency-specific behavioral thresholds accurately in infants and validating hearing aid fittings. Until evidence is sufficient to recommend the ASSR as primary electrophysiological measure of hearing in infants, the ASSR should be used in conjunction with the ABR – following a test battery approach in the diagnostic process of hearing loss in infants. The ASSR further shows great promise in validating hearing aid fittings, but this specific application of the ASSR needs further research evidence on large groups to validate the procedure.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
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  00front.pdf 65.58 Kb 00:00:18 00:00:09 00:00:08 00:00:04 < 00:00:01
  01chapter1.pdf 121.15 Kb 00:00:33 00:00:17 00:00:15 00:00:07 < 00:00:01
  02chapter2.pdf 604.99 Kb 00:02:48 00:01:26 00:01:15 00:00:37 00:00:03
  03chapter3.pdf 150.55 Kb 00:00:41 00:00:21 00:00:18 00:00:09 < 00:00:01
  04chapter4.pdf 387.53 Kb 00:01:47 00:00:55 00:00:48 00:00:24 00:00:02
  05chapter5.pdf 84.68 Kb 00:00:23 00:00:12 00:00:10 00:00:05 < 00:00:01
  06back.pdf 195.00 Kb 00:00:54 00:00:27 00:00:24 00:00:12 00:00:01

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