The influence of hearing loss on directional hearing.

Fifty patients with cochlear hearing loss were tested with phase audiometry. Thirty-three of the patients had unilateral hearing loss at 500 Hz and 17 bilateral, symmetrical hearing loss at 500 Hz. Those patients who had slight hearing loss (less than 40 dB HL) had as a rule normal directional hearing. Those who had hearing loss exceeding 40 dB HL at 500 Hz usually had abnormal directional hearing. The sound lateralization ability was independent of whether the hearing loss was unilateral or bilateral.