Despite the commonly observed condition of middle and inner ear barotrauma among divers, there is little evidence of insidious and permanent development of sensorineural hearing loss associated with diving. An audiometric survey was performed on a group of 120 divers and 166 non divers from the Royal Malaysian Naval Base in Lumut, West Malaysia between July to December 1991. The results of this survey revealed that insidious development of high frequency sensorineural hearing loss may be associated with diving. At frequencies 4000, 6000 and 8000 Hz the divers had higher mean hearing levels than non divers and their hearing at those frequencies seemed to deteriorate faster. The etiology of this insidious hearing loss is multifactorial and may be related to inner ear barotrauma, decompression sickness or noise-induced deafness.