Masking Level Difference: test-retest reliability assessment in normal hearing female university students

Abstract

Purpose: To verify the test-retest reliability of the Masking Level Difference in normal hearing female university students. Methods: Prospective descriptive study with 78 young female adults without hearing complaints, submitted to the compact disc version of the Masking Level Difference by Auditec of Saint Louis. The threshold was determined by the difference between signal-to-noise ratios at hearing thresholds found in the antiphasic and homophasic conditions. The test was applied by the same examiner in two moments (test and retest) with an interval of seven to 14 days between them. Inferential statistical analysis included comparison of test and retest situations using Student’s t test for paired samples, calculation of the intraclass correlation coefficient and calculation of 95% confidence intervals for signal-to-noise ratios at hearing thresholds found in the antiphasic and homophasic conditions and for masking level difference. Results: The average signal-to-noise ratio at hearing threshold in the homophasic condition was −12.59 dB and −12.46 dB in the Test and Retest situations, respectively, and −21.54 dB and −21.08 dB in the antiphasic condition. The average value in the final Masking Level Difference result was 8.95 dB in the Test and 8.74 dB in the Retest. Intraclass correlation coefficient values obtained were 0.436, 0.625 and 0.577 for homophasic, antiphasic and Masking Level Difference conditions, respectively. Conclusion: The Masking Level Difference showed moderate test-retest reliability in normal hearing adults female university students.