Problems in assessing the audiogram in patients with severe hearing impairment

Abstract

AbstractSevere hearing impairment (SHI) is an impairment of hearing in which the air conduction mean over 0.5–4 kHz in the better hearing ear lies between 70 and 90 dB. Masking of bone and air conduction thresholds is seldom possible with SHI, leading to difficulties in assessing the pure tone audiogram whenever there is a potential air bone gap in either ear.An audiological survey of 83 patients with severe hearing impairment was conducted. In 16 per cent of patients there was no possibility of a material air bone gap in either ear and no difficulty in interpreting the audiogram. In 23 (28 per cent), the audiogram was consistent with, but did not prove the presence of, an air bone gap in the poorer hearing ear. In 25 patients (30 per cent of 108) the better hearing ear could not be determined, and in 22 (27 per cent) a profound sensorineural impairment in the poorer hearing ear could not be excluded. The implications of this for the otologist are discussed.