Perception of Environmental Sound by Young Deaf and Hard-of-Hearing People: Listening at Different Noise Levels

It is difficult to be aware of the auditory signals of everyday life when one has a hearing impairment. In this study, we investigated which everyday acoustic signals are difficult for young deaf and hard of hearing (D/HoH) people to listen to. The participants were fifteen university students between the ages of 19 and 22. The auditory background varied (hearing aids, cochlear implants, bilateral hearing loss). Listening tests were conducted at different signal-to-noise ratios (SNR). The materials were clean sounds without noise and recorded sounds with noise (recorded in Taiwan and Japan). The materials were presented from loudspeakers in the classroom. The loudness of sounds was approximately 75 dBA at 1 m for the nearest person. Participants were asked to write down the name of the sound. The degrees of familiarity, confidence, and awareness were also assessed using a 5-point Mean Opinion Score (MOS). The results showed that the correct response rate tended to be high for sounds with good SNR. Significant correlations with the correct response rate were found for all three scores. From this result, we found that even if they thought the sound was easy to hear or they had confidence, they still listened to it as the wrong sound. For unfamiliar sounds, the percentage of correct responses is low. In this way, it is difficult for D/HoH people to passively recognize environmental sounds, and it is important to understand the environmental sounds around them through learning.