Asymmetric hearing loss in a random population of patients with mild to moderate sensorineural hearing loss

Objectives: We evaluated the correlation of asymmetric hearing loss, in a random population of patients with mild to moderate sensorineural hearing loss, to several clinical factors such as age, sex, handedness, and noise exposure. Methods: We randomly selected, from 8 hearing institutes in Israel, 429 patients with sensorineural hearing loss of at least 30 dB at one frequency and a speech reception threshold not exceeding 30 dB. Patients with middle ear disease or retrocochlear disorders were excluded. The results of audiometric examinations were compared binaurally and in relation to the selected factors. Results: The left ear's hearing threshold level was significantly higher than that of the right ear at all frequencies except 1.0 kHz (p < .05). One hundred fifty patients (35%) had asymmetric hearing loss (more than 10 dB difference between ears). In most of the patients (85%) the binaural difference in hearing threshold level, at any frequency, was less than 20 dB. Conclusions: Age, handedness, and sex were not found to be correlated to asymmetric hearing loss. Noise exposure was found to be correlated to asymmetric hearing loss.