Skip to main content

Research Repository

Advanced Search

Contralateral routing of signals disrupts monaural level and spectral cues to sound localisation on the horizontal plane

Pedley, Adam J.; Kitterick, P�draig T.

Authors

Adam J. Pedley

P�draig T. Kitterick



Abstract

Objectives: Contra-lateral routing of signals (CROS) devices re-route sound between the deaf and hearing ears of unilaterally-deaf individuals. This rerouting would be expected to disrupt access to monaural level cues that can support monaural localisation in the horizontal plane. However, such a detrimental effect has not been confirmed by clinical studies of CROS use. The present study aimed to exercise strict experimental control over the availability of monaural cues to localisation in the horizontal plane and the fitting of the CROS device to assess whether signal routing can impair the ability to locate sources of sound and, if so, whether CROS selectively disrupts monaural level or spectral cues to horizontal location, or both.

Design: Unilateral deafness and CROS device use were simulated in twelve normal hearing participants. Monaural recordings of broadband white noise presented from three spatial locations (-60°, 0°, and +60°) were made in the ear canal of a model listener using a probe microphone with and without a CROS device. The recordings were presented to participants via an insert earphone placed in their right ear. The recordings were processed to disrupt either monaural level or spectral cues to horizontal sound location by roving presentation level or the energy across adjacent frequency bands, respectively. Localisation ability was assessed using a three-alternative forced-choice spatial discrimination task.

Results: Participants localised above chance levels in all conditions. Spatial discrimination accuracy was poorer when participants only had access to monaural spectral cues compared to when monaural level cues were available. CROS use impaired localisation significantly regardless of whether level or spectral cues were available. For both cues, signal re-routing had a detrimental effect on the ability to localise sounds originating from the side of the deaf ear (-60°). CROS use also impaired the ability to use level cues to localise sounds originating from straight ahead (0°).

Conclusions: The re-routing of sounds can restrict access to the monaural cues that provide a basis for determining sound location in the horizontal plane. Perhaps encouragingly, the results suggest that both monaural level and spectral cues may not be disrupted entirely by signal re-routing and that it may still be possible to reliably identify sounds originating on the hearing side.

Citation

Pedley, A. J., & Kitterick, P. T. (2017). Contralateral routing of signals disrupts monaural level and spectral cues to sound localisation on the horizontal plane. Hearing Research, 353, 104-111. https://doi.org/10.1016/j.heares.2017.06.007

Journal Article Type Article
Acceptance Date Jun 13, 2017
Online Publication Date Jun 21, 2017
Publication Date Sep 30, 2017
Deposit Date Jun 20, 2017
Publicly Available Date Mar 28, 2024
Journal Hearing Research
Print ISSN 0378-5955
Electronic ISSN 1878-5891
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 353
Pages 104-111
DOI https://doi.org/10.1016/j.heares.2017.06.007
Keywords Monaural Localisation, Contralateral Routing of Signals (CROS), Monaural level cues, Monaural spectral Cues, Unilateral deafness
Public URL https://nottingham-repository.worktribe.com/output/885768
Publisher URL http://www.sciencedirect.com/science/article/pii/S0378595516306098

Files


HearRes_Pedley_Kitterick_2017.pdf (4.7 Mb)
PDF

Version
AM - Accepted Manuscript



Signals 1-s2.0-S0378595516306098-main.pdf (907 Kb)
PDF

Version
NA - Not Applicable (or Unknown)


HearRes_Pedley_Kitterick_2017.pdf (4.8 Mb)
PDF

Version
NA - Not Applicable (or Unknown)




You might also like



Downloadable Citations