Скрининговый метод оценки пространственной и временной разрешающей способности слуха при локализации движения по азимутальной координате

Abstract

A screening method for assessment of spatial and temporal resolution of the auditory system in case of azimuthal movement localization has been suggested and approbated in this paper. An approach of free-field sound source movement modeling was chosen. It is based on change of volume balance of wideband noise bursts on two loudspeakers, placed in front of the subject and separated by 60o azimuthal angle. An assessment of minimum audible movement angles and temporal thresholds for moving sound images was performed with the usage of an adaptive psychoacoustic procedure in ranges of velocities and trajectories of sound images the hearing system most sensitive to. The assessment was performed with participation of 11 healthy adult subjects for two types of signals: 1) control signals with flat spectrum and 2) signals with the reduced fraction of high-frequencies which corresponded to moderate sensorineural hearing loss. Minimum audible movement angles were 1.3o in average, and individual temporal thresholds did not exceed 0.1 s. Both these values did not depend on spectral profile of the signals. The time for assessment of one threshold was about 1.5 minutes. Preliminary approbation of the method suggested by us on the group of six patients with sensorineural hearing loss revealed a several times increase of temporal thresholds in comparison with the same thresholds for normally hearing subjects. Duration of the experiment for assessment of one threshold for patients did not differ from subjects with normal hearing. Thus, the suggested method allows quick assessment of spatial hearing condition in both healthy subjects and patients with hearing loss.