Design and Evaluation of Instrument Sound Identification Difficulty for the Deaf and Hard-of Hearing

This study investigates the level of difficulty in identifying listening to 16 different instrumental sounds in moderate to severe deaf and hard-of-hearing (DHH) subjects. Previous studies have suggested that DHH listeners' instrument identification difficulty level depends on the instrument group. Based on these findings, we hypothesized that timbre identification for similar instruments (e.g., two plucked string instruments) would be more difficult than that between dissimilar instruments (e.g., a plucked string instrument and a woodwind instrument). Based on this hypothesis, we designed the ISID, which is the difficulty of combining the sounds of four alternative instruments that comprise a group of instruments based on timbre similarity. In this study, we report the results of an instrumental timbre identification test developed using the ISID, which was administered to 20 patients with moderate to severe DHH, compare correct responses and the response times for each level of the ISID, and analyze and verify whether the identification of instrumental timbres exhibited any differences. The results show significant differences in the three levels of ISID based on the correct response rate and response time, thereby supporting the hypothesis.