Masking level differences under two different measurement conditions: A normative study of young adults

Objective: The objective of this study was to determine the gender-specific normative values of masking level difference (MLD) in healthy young adults for two different measurement conditions. Methods: One hundred young adults between the ages of 19 and 25 were included. Tympanometry, pure tone audiometry, and MLD were performed. In the first MLD measurement condition, the threshold level where the signal was out of phase and the noise was in phase (S pi No) was subtracted from the threshold level where the signal and noise were in phase (SoNo). In the second MLD measurement condition, the threshold level where the signal was in phase and the noise was out of phase (SoN pi) was subtracted from the threshold level where the signal and noise were in phase (SoNo). The mean test scores were obtained in decibels. Comparisons were made in terms of gender and conditions. Results: The mean MLD for SoNo-S pi No condition was 10.3 +/- 1.99 dB. For SoNo-SoN pi condition, the mean MLD was 6.72 +/- 2.38 dB. A significant difference was determined between the MLD under two different measurement conditions (p p <.05). There was no significant difference in terms of gender (p p >.05). Conclusion: Mean normative values of MLD test scores in gender-specific healthy young adults for two different measurement conditions are presented.