Localization and Spatial Discrimination in Children and Adolescents with Moderate Sensorineural Hearing Loss Tested without Their Hearing Aids

Abstract

The present study investigated two measures of spatial acoustic perception in children and adolescents with sensorineural hearing loss (SNHL) tested without their hearing aids and compared it to age-matched controls. Auditory localization was quantified by means of a sound source identification task and auditory spatial discrimination acuity by measuring minimum audible angles (MAA). Both low- and high-frequency noise bursts were employed in the tests to separately address spatial auditory processing based on interaural time and intensity differences. In SNHL children, localization (hit accuracy) was significantly reduced compared to normal-hearing children and intraindividual variability (dispersion) considerably increased. Given the respective impairments, the performance based on interaural time differences (low frequencies) was still better than that based on intensity differences (high frequencies). For MAA, age-matched comparisons yielded not only increased MAA values in SNHL children, but also no decrease with increasing age compared to normal-hearing children. Deficits in MAA were most apparent in the frontal azimuth. Thus, children with SNHL do not seem to benefit from frontal positions of the sound sources as do normal-hearing children. The results give an indication that the processing of spatial cues in SNHL children is restricted, which could also imply problems regarding speech understanding in challenging hearing situations.