Table of Contents Author Guidelines Submit a Manuscript
International Journal of Otolaryngology
Volume 2014, Article ID 248187, 8 pages
http://dx.doi.org/10.1155/2014/248187
Research Article

Contralateral Ear Occlusion for Improving the Reliability of Otoacoustic Emission Screening Tests

1Auditory Science Laboratory, Neuroscience and Mental Health Program, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8
2Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada M5S 1A1
3Department of Otolaryngology-Head and Neck Surgery, University of Toronto, 190 Elizabeth Street, Toronto, ON, Canada M5G 2N2

Received 10 October 2013; Accepted 28 November 2013; Published 12 January 2014

Academic Editor: Charles Monroe Myer

Copyright © 2014 Emily Papsin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Newborn hearing screening is an established healthcare standard in many countries and testing is feasible using otoacoustic emission (OAE) recording. It is well documented that OAEs can be suppressed by acoustic stimulation of the ear contralateral to the test ear. In clinical otoacoustic emission testing carried out in a sound attenuating booth, ambient noise levels are low such that the efferent system is not activated. However in newborn hearing screening, OAEs are often recorded in hospital or clinic environments, where ambient noise levels can be 60–70 dB SPL. Thus, results in the test ear can be influenced by ambient noise stimulating the opposite ear. Surprisingly, in hearing screening protocols there are no recommendations for avoiding contralateral suppression, that is, protecting the opposite ear from noise by blocking the ear canal. In the present study we have compared transient evoked and distortion product OAEs measured with and without contralateral ear plugging, in environmental settings with ambient noise levels <25 dB SPL, 45 dB SPL, and 55 dB SPL. We found out that without contralateral ear occlusion, ambient noise levels above 55 dB SPL can significantly attenuate OAE signals. We strongly suggest contralateral ear occlusion in OAE based hearing screening in noisy environments.