The sound exposure of classic orchestra musicians is not well assessed in Italy even though the protectionistic law includes all the working environments, as stated in the European Directive 2003/10/EC relative to the protection of workers against noise-induced damage. Scientific data in the literature show that the musicians are exposed to high daily personal exposure levels. These levels can systematically exceed the 85 dB(A) in the case of percussionists. In this study, preliminary results are shown relative to an experimental campaign performed in a lyric National Theatre. The aim of the study was the assessment of the risk due to high sound level in the theatre musicians and their cochlear functionality. The noise levels were measured by using wearable phonometers and multichannel sound analyzers. The signals were recorded during the whole working time in the rehearsal hall and in the fossa. The cochlear functionality was monitored before and immediately after rehearsal in a sample of volunteers by means of otoacoustic emission tests. Both TEOAE and DPOAE were measured using the ILO292 portable system. The data show that OAE-based tests can effectively discriminate between different classes of exposure. A good correlation was found between the daily exposure level and the DPOAE level.