Masking level difference among brazilian military personnel: a comparison between pilots and non-pilots

Abstract

Objectives The aims of this study were to investigate auditory habits and binaural interaction among pilot and non-pilot military personnel from the Brazilian Air Force. Design A cross-sectional study using (1) an auditory habits questionnaire to outline the groups auditory profile and (2) the masking level difference test (MLD, Auditec, Saint Louis®) to evaluate and compare the groups. Study Sample Forty military male personnel aged between 30–40 years old, all with normal hearing, comprising 20 pilots in the study group (SG), and 20 non-pilots, not exposed to noise, in the control group (CG). Results There was no significant difference between groups regarding auditory habits. In the MLD test, a significantly better performance under the homophasic condition (S0N0) was found in the SG. Under the antiphasic condition (SπN0) there were no differences between groups. This combination resulted in a significantly lower MLD in the SG compared to the CG. Conclusions Repeated exposure to conditions where active pilots have to learn to recognise speech in noisy backgrounds may lead to a better performance in the MLD’s homophasic condition (S0N0).