A simplified method, useful in clinical practice, is described in order to study the frequency selectivity in various conditions. The patient is asked to indicate the levels of pure tones which are necessary to mask completely the perception of an intermittent probe. The resulting psychoacoustic tuning curves are characterized by a more or less narrow bandwidth which reflects the ability to resolve simultaneously presented sounds. Several circumstances where these tuning curves are helpful, are presented: assessment of tinnitus, Menière's disease, unclear impairment of speech intelligibility. Therefore, this technique appears as a valuable tool which can be used in addition to the usual audiometric and electrophysiological tests battery.