In purely conductive hearing impairments the audiometric pattern of the air-conduction threshold is flat or slightly rising, whereas sensorineural impairment frequently shows an increase in the hearing loss at higher frequencies. This study shows that purely conductive defects due to discontinuity of the ossicular chain, can, under certain conditions, imitate the audiometric pattern of a high-tone sensorineural hearing loss. It is important that this type of conductive defect be recognized and not misinterpreted as sensory hearing loss. The presence of specific organic conductive defects can be demonstrated by Weber's lateralization test, and objective verification of the defect is best obtained by the acoustic stapedius reflex test and tympanometric measurement.