Audiometric asymmetry and tinnitus laterality
Article first published online: 23 MAR 2012
Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 122, Issue 5, pages 1148–1153, May 2012
How to Cite
Tsai, B. S., Sweetow, R. W. and Cheung, S. W. (2012), Audiometric asymmetry and tinnitus laterality. The Laryngoscope, 122: 1148–1153. doi: 10.1002/lary.23242
- Issue published online: 18 APR 2012
- Article first published online: 23 MAR 2012
- Manuscript Accepted: 18 JAN 2012
- Manuscript Revised: 10 JAN 2012
- Manuscript Received: 16 OCT 2011
- Coleman Memorial and Hearing Research, Inc.
- University of California, San Francisco
- receiver operating characteristic;
- Level of Evidence: 4.
To identify an optimal audiometric asymmetry index for predicting tinnitus laterality.
Retrospective medical record review.
Data from adult tinnitus patients (80 men and 44 women) were extracted for demographic, audiometric, tinnitus laterality, and related information. The main measures were sensitivity, specificity, positive predictive value (PPV), and receiver operating characteristic (ROC) curves.
Three audiometric asymmetry indices were constructed using one, two, or three frequency elements to compute the average interaural threshold difference (aITD). Tinnitus laterality predictive performance of a particular index was assessed by increasing the cutoff or minimum magnitude of the aITD from 10 to 35 dB in 5-dB steps to determine its ROC curve. Single frequency index performance was inferior to the other two (P < .05). Double and triple frequency indices were indistinguishable (P > .05). Two adjoining frequency elements with aITD ≥ 15 dB performed optimally for predicting tinnitus laterality (sensitivity = 0.59, specificity = 0.71, and PPV = 0.76). Absolute and relative magnitudes of hearing loss in the poorer ear were uncorrelated with tinnitus distress.
An optimal audiometric asymmetry index to predict tinnitus laterality is one whereby 15 dB is the minimum aITD of two adjoining frequencies, inclusive of the maximal ITD. Tinnitus laterality dependency on magnitude of interaural asymmetry may inform design and interpretation of neuroimaging studies. Monaural acoustic tinnitus therapy may be an initial consideration for asymmetric hearing loss meeting the criterion of aITD ≥ 15 dB.