10. Background
• Relationship between
PTA and speech
discrimination
• Speech discrimination
often poorer than
predicted by PTA
Rance, G., Auditory capacity in children with auditory neuropathy spectrum disorder, in Guidelines for Identification and Management of Infants and Young
Children with Auditory Neuropathy Spectrum Disorder, J. Northern, Editor. 2008: Aurora, Colorado. p. 17-19.
Rance G, Starr A. Pathophysiological mechanisms and functional hearing consequences of auditory neuropathy. Brain. 2015
11. What might it sound like?
• https://www.youtube.com/watch?v=ZZFERUP15w
E
12. Background
• Relationship between temporal processing ability
and speech discrimination
– Temporal processing particularly problematic
– Frequency and intensity processing sometimes spared
• Evidence that temporal processing ability predicts
speech discrimination ability
Rance, G., Corben, L., Barker, E., Carew, P., Chisari, D., Rogers, M., . . . Delatycki, M. B. (2010). Auditory perception in individuals with Friedreich's ataxia. Audiology and
Neuro-Otology, 15(4), 229-240.
Zeng, F. G., Oba, S., Garde, S., Sininger, Y. S., & Starr, A. (1999). Temporal and speech processing deficits in auditory neuropathy. Neuroreport, 10(16), 3429-3435.
Rance, G., McKay, C., & Grayden, D. (2004). Perceptual characterization of children with auditory neuropathy. Ear Hear, 25(1), 34-46.
Starr, A., Picton, T. W., Sininger, Y. S., Hood, L. J., & Berlin, C. I. (1996). Auditory neuropathy. Brain, 119 ( Pt 3), 741-753.
14. Communication
• Children with any degree of hearing loss may
have difficulties with language and communication
• Difficulties with aiding in ANSD
• Delayed aiding
Tomblin, J. B., Harrison, M., Ambrose, S. E., Walker, E. A., Oleson, J. J., & Moeller, M. P. (2015). Language Outcomes in Young Children with Mild to Severe
Hearing Loss. Ear Hear, 36 Suppl 1, 76S-91S.
Ching, T. Y., Day, J., Dillon, H., Gardner-Berry, K., Hou, S., Seeto, M., . . . Zhang, V. (2013). Impact of the presence of auditory neuropathy spectrum disorder
(ANSD) on outcomes of children at three years of age. International Journal of Audiology, 52(S2), S55-S64.
15. Brain structure and the auditory system
• Auditory processing
• Prediction of cochlear
implant outcome
• Unilateral hearing loss
• Auditory electrophysiology
16. Project aims
• Evaluate current auditory profile of children
diagnosed with ANSD
• Examine the relationships between auditory
processing, speech discrimination and brain
structure
18. Participants
• ANSD group
– Diagnosed on basis of present OAE and/or CM and
absent or abnormal ABR
• Control group
– Normal hearing
• Age 6-16 years
• Exclusions
– Current middle ear problems
– Progressive neurological condition
23. Results – parental questionnaire
• Children’s
Communication
Checklist – 2
• Two-thirds of ANSD
participants
identified as at risk
of significant
communication
problem by parental
questionnaire
A)
24. Results – evoked potentials
• Several participants no longer fitted profile of
ANSD
– Four fitted ANSD profile in at least one ear
– Six participants fitted profile of typical cochlear hearing
loss
– One had ‘normal’ evoked potential profile (and all
behavioural testing)
– Six had insufficient results to determine profile
25. Results – temporal processing
Test Auditory process Typical cochlear hearing loss
evidence
ANSD evidence Current ANSD study results
(compared to controls)
Frequency discrimination
(low frequency)
Phase locking Normal (Rance, Corben, Barker, et
al., 2010)
Poor (Rance, Corben,
Barker, et al., 2010)
Poor
Frequency discrimination
(high frequency)
Basilar membrane excitation Poor (Rance, Corben, Barker, et
al., 2010)
Normal (Rance, Corben,
Barker, et al., 2010)
Normal
Temporal integration Temporal discrimination Slope of integration function
shallower than for normally hearing
(Florentine, Fastl, & Buus, 1988;
Oxenham, Moore, & Vickers,
1997)
Normal (Zeng et al., 1999)
Difficulties detecting short
duration sounds only (Zeng
et al., 2005)
Poor
Amplitude modulation
detection
Temporal discrimination Mildly elevated (Rance, Corben,
Barker, et al., 2010)
Normal (Rance et al., 2004)
Normal at slow rate but poor
at high rate (Rance, Corben,
Barker, et al., 2010; Rance
et al., 2004)
Normal at slow rate but poor at
high rate
Tone detection in noise Interaction between timing
cues between two ears
Reduced but present (Hall &
Harvey, 1985)
Absent (Starr et al., 1996) Reduced but present
26. Speech discrimination
• PTA associated with speech-in-quiet scores but
not speech-in-noise scores
• Composite measure of temporal processing ability
associated with speech-in-quiet scores and
speech-in-noise scores
27. Results – imaging
• Cortical thickness correlations with speech-in-quiet
A) B) C)
28. Results – imaging
• Cortical thickness correlations with speech-in-noise
A) B)
30. Discussion
• Several participants no longer fit ANSD
electrophysiology profile
– ABR recovery
– Implications
• Residual central auditory pathway disruption?
• Disrupted auditory signal input during critical phases of
development?
• Name of disorder following recovery?
• Aiding/amplification?
31. Discussion
• Children diagnosed with ANSD have significant
speech discrimination problems in quiet and in
noise
– Related to temporal processing abilities
• Children diagnosed with ANSD have significant
communication problems
• Auditory experiences of children diagnosed with
ANSD are associated with brain structure
differences
32. Summary
• Complex hearing loss with various management
strategies
• Our understanding of ANSD and its
developmental consequences is increasing but
more research is needed
• Evidence base for management strategies is weak
and needs further research
33. Further research
• Gary Rance and Julien Zanin,
University of Melbourne
– Using Magnetic Resonance Imaging (MRI)
to develop neurodiagnostic techniques for
auditory neuropathy
