[Sound lateralization regarding amplitude and time factors in various forms of hearing loss].

The ability to localize the sound source was investigated in 70 patients with hypoacusis of various type and degree, using interaural differences in time and intensity. The dichotic method of signal presentation was employed which made it possible to separately vary sound excitation of each ear. Isolated use of interaural differences in terms of time and amplitude was investigated by measuring lateralization thresholds, i.e. minimal interaural differences in time and intensity perceived as a displacement of the acoustic image from the head midline. It was found that lateralization of the acoustic image in response to interaural time and intensity differences followed different patterns. The precision of time lateralization depended on the level of hearing impairment and on binaural hearing asymmetry with respect to tone perception thresholds. The precision of intensity lateralization was dependent on the type of hypoacusis. The lowest thresholds of intensity lateralization were seen in patients with chronic adhesive otitis while the highest thresholds were detected in patients with 1st degree otosclerosis. It is recommended to use tests for measuring lateralization thresholds in terms of time and intensity in order to perform differential diagnostics of hearing impairment and functional prediction of hearing improvement interventions in otosclerosis and chronic otitis.