Comparing the Accuracy and Speed of Manual and Tracking Methods of Measuring Hearing Thresholds
Gayla L Poling1, Theresa J Kunnel, Sumitrajit Dhar
11The Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, USA; and 2Loyola University's College of Arts and Sciences, Loyola University of Chicago, Chicago, Illinois, USA.
Objectives:
The reliability of hearing thresholds obtained using the standard clinical method (modified Hughson-Westlake) has been the focus of previous investigation given the potential for tester bias (). In recent years, more precise methods in laboratory studies have been used that control for sources of bias, often at the expense of longer test times. The aim of this pilot study was to compare test-retest variability and time requirement to obtain a full set of hearing thresholds (0.125 - 20 kHz) of the clinical modified Hughson-Westlake (manual) method with that of the automated, modified (single frequency) Békésy tracking method ().
Design:
Hearing thresholds from 10 subjects (8 female) between 19 to 47 years old (mean = 28.3; SD = 9.4) were measured using two methods with identical test hardware and calibration. Thresholds were obtained using the modified Hughson-Westlake (manual) method and the Békésy method (tracking). Measurements using each method were repeated after one-week. Test-retest variability within each measurement method was computed across test sessions. Results from each test method as well as test time across methods were compared.
Results:
Test-retest variability was comparable and statistically indistinguishable between the two test methods. Thresholds were approximately 5 dB lower when measured using the tracking method. This difference was not statistically significant. The manual method of measuring thresholds was faster by approximately 4 minutes. Both methods required less time (~ 2 mins) in the second session as compared to the first.
Conclusion:
Hearing thresholds obtained using the manual method can be just as reliable as those obtained using the tracking method over the large frequency range explored here (0.125 - 20 kHz). These results perhaps point to the importance of equivalent and valid calibration techniques that can overcome frequency dependent discrepancies, most prominent at higher frequencies, in the sound pressure delivered to the ear.
