Minimal time to determine moving sound source direction in patients with sensorineural hearing loss

Abstract

Minimal time to determine the direction of azimuthal motion was measured in normally hearing subjects and in patients with sensorineural hearing loss (SNHL). A moving sound image was formed by counter-directional change of the amplitude on two loudspeakers placed at 1.1 m in front of the listener by azimuthal angles of ±30° in a sound-treated room. The sound image moved from the central position to the left or to the right, or in the opposite direction along 24.2° arc. An adaptive psychoacoustic procedure was used in a diapason of sound images durations from 0.1 to 1.5 s with 0.1s step. All subjects with normal hearing (N = 11) had the minimal time of 0.1 s or lower. Patients demonstrated significantly higher minimal time: 0.4, 0.5 and 0.9 s in case of mild (N = 16), moderate (N = 16) and moderately severe (N = 12) SNHL, respectively (p < 0.001, p < 0.000 1, and p < 0.000 01, Mann-Whitney U Test). Patients were divided into groups in accordance with the WHO classification. Minimal times in patients with mild and moderate SNHL did not differ (p = 0.18, Mann-Whitney U Test), but both were lower than in patients with moderately severe SNHL (p < 0.01, Mann-Whitney U Test). [This work was supported by means of the State assignment (АААА-А18-118013090245-6).]