Background and ObjectivesThe purpose was to establish the test-retest reliability of word recognition score (WRS) using Korean standard monosyllabic word lists for adults (KS-MWL-A) recently developed based on the international standard for speech audiometry (ISO 8253-3:2012).Subjects and MethodsSubjects consisted of 159 adults aged to 18 to 25 years with normal hearing sensitivity. WRSs were obtained in 2 dB steps from the level of speech recognition thresholds to the level of 86% correct responses or greater. After one or two weeks, retest was performed. Correlation, confidence interval (CI) and prediction interval (PI) were calculated for the reliability.ResultsCorrelation coefficients were 0.88 for 50 test words, 0.76 for 25 and 0.61 for 10 words. Results also showed that 95% CIs and PIs were narrower for 25 and 50 test words than those for 10 test words.ConclusionsKorean WRS using the KS-MWL-A has high reliability for 25 and 50 test words, but relatively low for 10 words. It suggested that 95% CIs for each test words would be criteria for significant differences in WRS for groups and 95% PIs at each score of WRS could be utilized for a considerable difference for each individual at retest.

Background and ObjectivesThe band-importance function (BIF) refers to a value characterizing the relative importance of different frequencies to speech intelligibility. The purpose of this study was to derive the BIF for the Korean standard sentence lists for adults (KS-SL-A).Subjects and MethodsIn this study, sentences from the KS-SL-A were used as the speech material. Twenty-six normal-hearing Korean listeners participated and intelligibility scores in 8 filters with 3 signal-to-noise ratio conditions were obtained. Based on the intelligibility score percentages, the BIF for the KS-SL-A was derived by using an established protocol.ResultsBand-importance weights varied across frequency bands. The most important frequency region was around 316 Hz (20.0%), and the importance of the frequency bands below the center frequency (CF) of 1,778 Hz was 59.6%. Therefore, low frequencies below the CF of 1,778 Hz were more important than high frequencies above the CF of 1,778 Hz.ConclusionsThe BIF for KS-SL-A could be applied towards developing a hearing aid fitting formulae for Korean listeners.

Hearing aids are one of the most widely used treatment options for the hearing impaired and optimal outcomes of hearing aids are supported by comprehensive hearing aid fitting protocols. Currently, the term 'hearing aid fitting' is prevalently used among service and industry sectors with its comprehensive procedures not systematically explicated. In addition, a variety of non-normalized guidelines for hearing aid fitting has led to non-uniform care, outcome variability, and dissatisfaction of the use of hearing aids. The main purpose of the present study is to suggest a general framework of standardized practice for hearing aid fitting management including its pre- and post-fitting stages. The management framework centers on its fitting process with its prior steps of assessment as well as its posterior steps of follow-up, thereby eliminating diverging interpretations and non-uniform practices. Outcomes of this study are also expected to improve potential benefits such as quality of hearing aid fitting, user satisfaction, and cost effectiveness across relevant stakeholders.

Phonemes provide an interesting alternative to pure tones in hearing tests.We propose a new smartphone-based method for self-hearing assessment using the four Korean phonemes which are similar to the English phonemes /a/, /i/, /sh/, and /s/. We conducted tests on 15 subjects diagnosed with mild to severe hearing loss and estimated their conventional pure-tone hearing thresholds from their phoneme hearing thresholds using regression analysis. The phoneme-based self-hearing assessment was found to be sufficiently reliable in estimating the hearing thresholds of hearing impaired subjects. The difference between the hearing thresholds obtained through conventional pure-tone audiometry and those obtained using our method was 5.6 dB HL on average. The proposed hearing assessment was able to significantly reduce the mean test time compared to conventional pure-tone audiometry.

In this study, we proposed new self assessment of hearing loss in mobile phones and realized a function of compensation for hearing impaired person. The results of experiments on mobile phone showed that the proposed hearing test is sufficient to check hearing loss and the compensation based on the result of the proposed hearing test can improve speech intelligibility of hearing impaired persons.