Original Paper

Auditory Perception in Individuals with Friedreich's Ataxia
Gary Rance^a, Louise Corben^b, Elizabeth Barker^a, Peter Carew^a, Donella Chisari^a, Meghan Rogers^a, Richard Dowell^a, Saiful Jamaluddin^a, Rochelle Bryson^a, Martin B. Delatycki<sup>b

a</sup>Department of Otolaryngology, The University of Melbourne, and
^bMurdoch Children's Research Institute, Parkville, Vic., Australia

Address of Corresponding Author

Audiol Neurotol 2010;15:229-240 (DOI: 10.1159/000255341)

  Key Words

• Friedreich's ataxia
• Auditory perception
• Temporal processing
• Speech perception

  Abstract

Introduction: Friedreich's ataxia (FRDA) is an inherited ataxia with a range of progressive features including axonal degeneration of sensory nerves. The aim of this study was to investigate auditory perception in affected individuals. Methods: Fourteen subjects with genetically defined FRDA participated. Two control groups, one consisting of healthy, normally hearing individuals and another comprised of subjects with sensorineural hearing loss, were also assessed. Auditory processing was evaluated using structured tasks designed to reveal the listeners' ability to perceive temporal and spectral cues. Findings were then correlated with open-set speech understanding. Results: Nine of 14 individuals with FRDA showed evidence of auditory processing disorder. Gap and amplitude modulation detection levels in these subjects were significantly elevated, indicating impaired encoding of rapid signal changes. Electrophysiologic findings (auditory brainstem response, ABR) also reflected disrupted neural activity. Speech understanding was significantly affected in these listeners and the degree of disruption was related to temporal processing ability. Speech analyses indicated that timing cues (notably consonant voice onset time and vowel duration) were most affected. Conclusion: The results suggest that auditory pathway abnormality is a relatively common consequence of FRDA. Regular auditory evaluation should therefore be part of the management regime for all affected individuals. This assessment should include both ABR testing, which can provide insights into the degree to which auditory neural activity is disrupted, and some functional measure of hearing capacity such as speech perception assessment, which can quantify the disorder and provide a basis for intervention.

Copyright © 2009 S. Karger AG, Basel

  Author Contacts

Assoc. Prof. Gary Rance
Department of Otolaryngology, The University of Melbourne
550 Swanston Street
Parkville, Vic. 3010 (Australia)
Tel. +61 3 9035 5342, Fax +61 3 9662 3312, E-Mail grance@unimelb.edu.au

  Article Information

Received: April 28, 2009
Accepted after revision: August 21, 2009
Published online: November 5, 2009
Number of Print Pages : 12
Number of Figures : 5, Number of Tables : 5, Number of References : 38