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COAE thresholds: 1. Effects of equal-amplitude versus subtraction methods
1Department of Communication Sciences and Disorders, Syracuse University, New York, USA.
Journal of Speech, Language, and Hearing Research : JSLHR
|November 5, 1997
Summary
The equal-amplitude click method provides more accurate click-evoked otoacoustic emissions (COAEs) thresholds for hearing loss identification than the subtraction method. This method yields lower noise floors and higher COAE amplitudes, improving test efficiency.
Area of Science:
- Audiology
- Otoacoustic Emissions
- Hearing Diagnostics
Background:
- Click-evoked otoacoustic emissions (COAEs) are used to identify hearing loss.
- Previous studies on COAEs' ability to predict behavioral thresholds have yielded inconsistent results.
- Methodological inconsistencies in COAE threshold estimation may contribute to these equivocal findings.
Purpose of the Study:
- To investigate the impact of two stimulus presentation methods on COAE threshold testing.
- To compare COAE threshold estimation using equal-amplitude clicks versus a subtraction method.
- To determine the optimal method for reliable COAE threshold assessment.
Main Methods:
- Measured COAE and noise floor levels in 15 participants.
- Utilized both equal-amplitude click stimuli and a subtraction method for eliciting COAEs.
- Analyzed broadband COAEs in 1/3 octave bands to calculate input/output functions and thresholds.
Main Results:
- The equal-amplitude method resulted in approximately 6 dB lower mean noise floor levels compared to the subtraction method.
- COAEs evoked by the equal-amplitude method were generally higher in amplitude.
- COAE thresholds were significantly lower using the equal-amplitude method, suggesting greater sensitivity.
Conclusions:
- The equal-amplitude click method is preferable for COAE threshold testing.
- This method offers lower noise floors and larger COAE amplitudes, enhancing test efficiency and accuracy.
- Improved COAE threshold estimation can lead to more reliable prediction of behavioral hearing thresholds.
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