The Band-Importance Function for the Korean Standard Sentence Lists for Adults

진인기,이정학,이경원,김진숙,김동욱,손준일,이경주 대한청각학회 2016 Journal of Audiology & Otology Vol.20 No.2

Background and Objectives: The 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 (KSSL- A). Subjects and Methods: In 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. Results: Band-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. Conclusions: The BIF for KS-SL-A could be applied towards developing a hearing aid fitting formulae for Korean listeners.

The Dynamic Range for Korean Standard Sentence Material: A Gender Comparison in a Male and a Female Speakers

진인기 대한청각학회 2015 Journal of Audiology & Otology Vol.19 No.2

Background and Objectives: The purpose of this study was to identify differences between the dynamic ranges (DRs) of male and female speakers using Korean standard sentence material. Consideration was especially given to effects within the predefined segmentalized frequency- bands. Materials and Methods: We used Korean standard sentence lists for adults as stimuli. Each sentence was normalized to a root-mean-square of 65 dB sound pressure level. The sentences were then modified to ensure there were no pauses, and the modified sentences were passed through a filter bank in order to perform the frequency analysis. Finally, the DR was quantified using a histogram that showed the cumulative envelope distribution levels of the speech in each frequency band. Results: In DRs that were averaged across all frequency bands, there were no significant differences between the male and the female speakers. However, when considering effects within the predefined frequency bands, there were significant differences in several frequency bands between the DRs of male speech and those of female speech. Conclusions: This study shows that the DR of speech for the male speaker differed from the female speaker in nine frequency bands among 21 frequency bands. These observed differences suggest that a standardized DR of male speech in the band-audibility function of the speech intelligibility index may differ from that of female speech derived in the same way. Further studies are required to derive standardized DRs for Korean speakers.

Comparison of a Hearing Aid Fitting Formula Based on Korean Acoustic Characteristics and Existing Fitting Formulae

진인기,이경원,김진숙,김동욱,손준일,이정학 한국청각언어재활학회 2017 Audiology and Speech Research Vol.13 No.3

Purpose: Most existing hearing aid (HA) fitting formulae were developed based on English. However, Korean language has different acoustic characteristics compared to English. This study aimed to develop Korean language-specific hearing aid fitting formula (Hallym Audiology Institute-version 1, HAI-v1) and to compare speech perception, clarity, and overall preference between the HAI-v1 and established fitting formulae [National Acoustic Laboratories’ nonlinear fitting procedure, version 2 (NAL-NL2) and Desired Sensation Level, version 5.0 (DSL5.0)]. Methods: Gains for the HAI-v1 were determined to reach the gain around the medium to the two-thirds portion in the dynamic range of conversational speech level for soft, medium, and loud levels using loudness growth for Koreans who have sensorineural hearing loss (SNHL). Twenty-four people with SNHL participated in this study. Reception thresholds of sentences (RTSs) and preferences (clarity and overall preference) were evaluated, once with HAI-v1 setting, once with NAL-NL2 setting, and once with DSL5.0 setting, in random order. Then, results of RTSs and preferences across HA fitting formulae were compared. Results: There were no statistical differences for RTSs with and without noise in all HA fitting formulae. For clarity, more participants preferred sounds with HAI-v1 or NAL-NL2 than sounds with DSL5.0. For overall preference, more participants preferred sounds with HAI-v1 than sounds with NAL-NL2 or DSL5.0. Conclusion: Results of this study suggest that language-specific HA fitting formula may provide better HA outcomes for people who use different languages.

화자변수가 건청성인의 어음청각검사 인지도에 미치는 영향

진인기,이재희 한국청각언어재활학회 2010 Audiology and Speech Research Vol.6 No.1

The purpose of this study was to examine effects of talker variability manipulated by the number of target talkers (two- versus multitalker) on the speech recognition results of Korean Speech Audiometry. Korean Speech Audiometry (KSA, www.kops.co.kr) included three types of the speech test materials (one-, two-syllable words, and sentences), and was recorded digitally in CDs by either a male or female talker. Given that some researchers have reported a significant effect of talker variability on speech recognition accuracy, we recorded all the speech materials in CDs by 20 talkers (10 male and 10 female). The effect of talker variability was then determined by comparing speech recognition performances of 5 young normal-hearing listeners by two-talker (in KSA CD) versus 20-talker conditions from -5 to 40 dB HL in 5 dB steps. The results showed that speech recognition accuracy of young normal-hearing listeners did not significantly differ in conditions for each of the three speech materials at each presentation level. This indicated important clinical implications of CD materials in KSA for the speech audiometric tests.

한국어 단음절과 문장, 영어 문장을 이용한 장기평균어음스펙트럼 비교 연구

진인기,이재희 한국청각언어재활학회 2010 Audiology and Speech Research Vol.6 No.2

The purpose of this study was to compare long-term average speech spectrum (LTASS) of Korean monosyllabic words, sentences, and English sentences. For Korean speech material, 200 monosyllabic words and 80 sentences were recorded by 20 native talkers of Korean (10 males, 10 females). As English speech material, 100 IEEE Harvard Psychoacoustic Sentences spoken by 20 native talkers of English (10 males, 10 females) were used. The LTASS was analyzed via one-third octave band filters from 150 Hz to 5,000 Hz. The following results were obtained. 1) LTASS of 10 male talkers showed larger differences at higher frequencies, regardless of speech material whereas LTASS of 10 females had the largest difference at 125 Hz. 2) The male LTASS of three speech materials did not significantly differ at one-third octave scales from 150 Hz to 5,000 Hz, except four frequencies (125 Hz, 160 Hz, 500 Hz, and 4,000 Hz). 3) The female LTASS was also similar at all frequencies from 150 Hz to 5,000 Hz, regardless of speech material. 4) The LTASS averaged across three materials showed a significant difference depending on the target-talker gender, especially the largest difference at 125 Hz. 5) The LTASS of Korean monosyllabic words, sentences, and English sentences did not significantly differ except three frequencies (160, 500, 630 Hz). Those results support previous finding of the universal characteristics of LTASS (Byrne et al., 1994), regardless of language.

한국어 이명주요기능설문지의 검사 - 재검사 신뢰도 검증 및 간소화 버전 제안

허소희,진인기 한국청각언어재활학회 2019 Audiology and Speech Research Vol.15 No.4

Purpose: The purpose of this study is to verify the test-retest reliability of the Korean version of the tinnitus primary function questionnaire (K-TPFQ) and to propose a simplified version of the K-TPFQ. Methods: In the test-retest reliability measure of the K-TPFQ, 31 participants were asked to complete the K-TPFQ on two occasions. Correlation between the results of the two questionnaires was confirmed by Pearson correlation coefficient. Then, a total of 110 subjects participated in the proposed, simplified version. Following factor analysis of the K-TPFQ, three items with high factor loadings for each subscale were selected as simplified version items. Internal consistency and validity were analyzed for the 12 items of the simplified version of the K-TPFQ. Results: The results of the test-retest reliability analysis of K-TPFQ showed significantly high correlations in all items, subscales, and total scores (r = 0.598-0.927). As a result of factor analysis, all items in each subscale showed high communalities. Therefore, we extracted 3 items with high content validity and high factor loadings from each subscale and adopted a total of 12 items for the simplified version. The results of the internal consistency test of the simplified version showed good validity and significantly high internal consistency of all items and subscales (α = 0.839-0.950). Conclusion: This study verified the high reliability and validity of the K-TPFQ. Therefore, it can be used to effectively evaluate the secondary effects of tinnitus in domestic clinics. In addition, the simplified version will reduce the time for evaluating tinnitus sufferers.

어음명료지수의 측정과 적용

김건구,진인기 한국청각언어재활학회 2015 Audiology and Speech Research Vol.11 No.3

Speech Intelligibility Index (SII) is a model that predicts speech intelligibility based on a person’s hearing thresholds and audible speech cues in given frequency bands. The SII is able to predict how loss of audibility due to hearing loss affects intelligibility of speech. Thus, the SII has been applied clinically in evaluation and fitting for hearing aids to quantify how much audibility is compensated by amplification. Although the SII known as Articulation Index was first introduced during the 20th century, calculation methods and aspects of the SII have been continually refined and developed for clinical use. This article provides (1) a brief history of the SII, (2) a view of components and calculation methods of the SII, (3) a review of applications for clinical use, and (4) a discussion of limitations and aspects that need to be considered for clinical applications in future.

독립발화조건에 따른 한국어 모음 길이 연구

이경주,진인기 한국청각언어재활학회 2016 Audiology and Speech Research Vol.12 No.3

Purpose: The purpose of this study was to measure durations of Korean vowels. Methods: Using a speech-recording program, 20 normal-hearing participants recorded 20 Korean vowels. Each vowel was recorded five times and the second, third, and fourth recorded vowel durations were used for analysis of durations. Results: On average, vowel durations for female speakers were longer than the durations for male speakers. Specifically, 11 vowel durations for female speakers were significantly longer than the durations for male speakers and the other nine vowel durations for female speakers were not. In addition, across-vowel differences in duration were evident not only for male speakers but also for female speakers. Generally, durations of diphthongs were longer than durations of monophthongs. Conclusion: The results of this study provide information about effects of gender and vowels in vowel durations. Vowel durations may be one factor to discriminate vowels.

명료어음과 일반 발성법에 의해 산출된 주파수중요함수와 전달함수 비교

오홍엽,허소희,진인기 한국청각언어재활학회 2019 Audiology and Speech Research Vol.15 No.3

Purpose: This study compared band-importance function (BIF) and transfer function (TF) derived using clear and conversational speech. Methods: There were 156 participants in this study: 78 for the clear speech group and the others for the conversational speech group. The data used to derive BIF and TF were obtained using the same procedure as the previous study. Sentences from Speech Perception In Noise test were used as stimuli. Intelligibility scores were measured via 42 filters at five signal-to-noise ratios. The BIFs and TFs for clear and conversational speech were derived using a nonlinear optimization procedure. Then those for the different production methods were compared. Results: The BIF and TF for different production methods have different characteristics. For BIF, the highest weights of importance for clear speech ranged between 200 Hz and 400 Hz and the highest weights for conversational speech ranged between 510 Hz and 770 Hz. The maximum different band-importance weight for the two production methods was 1.92%p at a center frequency of 2,150 Hz. The TF for clear speech was steeper than the TF for conversational speech. Conclusion: The results of the current study provide information on the degree to which the clear speech is more intelligible according to the listener’s audibility compared to that for conversational speech. Audiologists and hearing professionals will use this information, when considering the communication strategy for people with hearing loss.

Acoustic Features and Cortical Auditory Evoked Potentials according to Emotional Statues of /u/, /a/, /i/ Vowels

김춘혁,이승완,진인기,김진숙 대한청각학회 2018 Journal of Audiology & Otology Vol.22 No.2

Although Ling 6 sounds are often used in the rehabilitationprocess, its acoustic features have not been fully analyzed and represented in cortical responses. Current study was aimed to analyze acoustic features according to gender andemotional statuses of core vowels of Ling 6 sounds, /u/, /a/, and /i/. Cortical auditoryevoked potentials (CAEPs) were also observed in those vowels. Subjects and Methods:Vowel sounds /u/, /a/, and /i/ out of Ling 6 sounds representing low, middle and high frequencieswere recorded from normal 20 young adults. The participants watched relevant videosfor 4-5 minutes in order for them to sympathize emotions with anger (A), happiness (H),and sadness (S) before producing vowels. And without any emotional salience, neutrally productionwas performed. The recording was extracted for 500 ms to select pure vowel portionof production. For analysis of CAEP, the latencies and amplitudes of P1, N1, P2, N2, N1-P2were analyzed. Results: Intensities of /u/, /a/, and /i/ were 61.47, 63.38, and 60.55 dB. Theintensities of neutral (N), H, A, S were 60.60, 65.43, 64.21, and 55.75 dB for vowel /u/, vowel/a/ were 61.80, 68.98, 66.50, and 56.23 dB, and vowel /i/ were 59.34, 64.90, 61.90, and56.05 dB. The statistical significances for vowel and emotion were found but not for gender. The fundamental frequency (F0) of vowels for N, A, H, and S were 168.04, 174.93, 182.72,and 149.76 Hz and the first formant were 743.75, 815.59, 823.32, and 667.62 Hz. The statisticalsignificance of F0 was found by vowel, emotion, and gender. The latencies and amplitudesof CAEP components did not show any statistical significance according to vowel. Conclusions: Ling 6 sounds should be produced consistently in the rehabilitation processfor considering their difference of intensities and frequencies according to speaker’s emotionsand gender. The vowels seemed to be interpreted as tonal stimuli for CAEP components ofthis study with similar acoustic features among them. Careful selection of materials is necessaryto observe meaningful conclusion of CAEP measurement with vowel stimuli.