Frequency-based categorization of environmental sounds: Preliminary findings in clinical population

Abstract

Abstract Context: Environmental sound research shows promising results in understanding auditory perception. A frequency-based category of environmental sounds can aid in assessing auditory disorders. Aims: The aim of this study was to categorize the sounds according to their frequency characteristics and assess preliminary findings in clinical population. Settings and Design: This was a cross-sectional study design. Subjects and Methods: Phase I consisted of selection and validation of culturally relevant sounds from two existing tests: Familiar Environmental Sound Test (FEST) and FEST-Identification, Phase II categorized these sounds based on the frequency characteristics obtained by correlating subjective pitch and spectral peaks – Spearman’s rank correlation of pitch judgment and spectral peaks, and Phase III assessed the sounds on 25 normal-hearing individuals, 15 with sensorineural hearing loss (SNHL), and 15 with auditory neuropathy spectrum disorder (ANSD). Between-group and within-group comparisons were carried out using one-way ANOVA and independent t -test, respectively. Results: Out of 185 exemplars, sounds from 37 distinct sources were retained after analyses. Pitch judgment of these sounds correlated with spectral peaks based on which they were categorized into low- and high-frequency sounds. The normal-hearing group showed the best performance, followed by SNHL and ANSD. Performance was significantly poorer on the low-frequency sounds in the clinical groups. Conclusions: The frequency-based categorization of environmental sound test is useful in understanding frequency-specific deficits in SNHL and ANSD. It can serve as a nonverbal tool in assessment and intervention of auditory disorders.