INTRODUCTION: The Masking Threshold Differential (MLD - Masking Level Difference) is part of a battery of behavioral tests for central auditory processing. It consists in determining the hearing threshold for presenting a pure tone pulsating in both ears at the same time as a masking noise is presented. OBJECTIVE: To establish reference values for the test of temporal masking (MLD) in individuals aged 18 to 39 years old. METHODS: We searched the difference between hearings thresholds obtained in two different conditions of presentation of the signal / noise ratio. The MLD refers to the threshold detection signal which occurred under two masking - SN (homophasic) and SðN (antiphasic) are binaural phase and out of phase .. RESULTS: In 30 subjects, 73.34% had values equal to or greater than 7 dB. There was no statistically significant difference in the comparison between sexes (p <0.05). CONCLUSION: The higher values of MLD and / or equal to 7 dB were considered normal, corroborating with the literature on the subject who reported that lower values and / or equal to 6dB for adults are considered abnormal. Individuals with values below the normal range will be investigated and referred to Otolaryngological. This pilot study highlights the importance of continuity in the study testing the ability of binaural interaction (MLD), which proves to be closely linked with the ability of the sound source localization and speech recognition in noise.