The purpose of the present study was to investigate whether function of compression threshold (CT) affects the scores of Korean consonant perception test (KCPT) and sound quality in quiet and noisy environments. Methods: The subjects were 18 adults with sensorineural hearing loss, average age of 56.8 years, word recognition more than 40% and pure tone average of 54.3 dB HL. The hearing aids used in this study were behind-the-ear type hearing aid with more than 4 channels. After randomly adjusting the CT to 55, 65, 75 dB SPL in quiet and white noise environments (+6 dB signal-to-noise ratio), the scores of KCPT and preferences (clarity, sound quality, and loudness of noise) were evaluated. Results: The CT of 55 dB SPL and 65 dB SPL scored higher KCPT than CT of 65 dB SPL in noisy environment. In quiet environment, however, there was no difference in Korean consonant recognition score based on its CT. In the preferences assessment, CT of 55 dB SPL showed greater loudness of noise than CT of 75 dB SPL. However, the clarity and sound quality did not vary on CT in quiet and noisy environments. Conclusion: Based on the results of this study, it has been confirmed that CT may affect the recognition of Korean speech sounds and the loudness of noise. Therefore, the control of CT should be considered when adjusting electroacoustic elements of the multi-channel hearing aid.

We have reported one case of improvement in word recognition score (WRS) and sentence recognition score (SRS) in an elderly hearing aid user who had difficulty in communicating with others even after having a hearing aid fitted. Six weeks of training was conducted using environmental sounds, stories, and questions. Auditory training was conducted twice a week in hearing aid fitting room and total training time in each session was 40 minutes, including checking hearing aids, pre-training counseling, auditory training, and post-training counseling. After three weeks of auditory training, the WRSs of the left and right ear with headphone were changed 28% to 48% and 28% to 40%, respectively. After six weeks of training, SRSs in the acoustic room were improved 47.5% to 77.5% with hearing aids on both sides. And the Korean version of profile of hearing aid benefit scores after six weeks of training were 15.3% for easy communication, 62.3% for background noise, 34.3% for aversiveness, and 50.0% for localization except reverberation situation. This study showed that an elderly hearing aid user has improved communication skills, despite the short period of training. In addition, various training tools and methods are required to ensure that the subject does not lose interest in auditory training, and if the duration and place for the auditory training are limited, a training application on a personal computer or smartphone may facilitate auditory training.