Effect of noise and reverberation on speech recognition and listening effort for older adults

Kwak, Chanbeom,Han, Woojae,Lee, Jihyeon,Kim, Jinsook,Kim, Sungkyun John Wiley Sons Australia, Ltd 2018 GERIATRICS & GERONTOLOGY INTERNATIONAL Vol.18 No.12

<P><B>Aim</B></P><P>The purpose of the present study was to evaluate the speech recognition ability and degree of listening effort for older adults in noisy and reverberating environments.</P><P><B>Methods</B></P><P>A total of 80 participants (40 older and 40 younger adults) participated in a sentence recognition test under 20 conditions with four levels of background noise and five levels of reverberation time. In each condition, the degree of listening effort was self‐reported using a 5‐point Likert scale.</P><P><B>Results</B></P><P>The older and younger groups showed that both the error percentage of the sentence recognition task and scale of the listening effort increased as the background noise and reverberation time increased. In the sentence recognition task, the older group was more affected by the reverberation condition than the noisy background compared with their younger counterparts. For the listening effort, the older group had higher scales than the younger group in all conditions, thereby explaining that they required significant effort during the listening task.</P><P><B>Conclusions</B></P><P>The older adults had poorer speech perception ability and required more listening effort than their younger counterparts in all conditions. Reverberation reversely significantly affected the speech recognition and listening effort for the older adults when compared with the background noise, suggesting that an appropriate level of noise and reverberation should be considered for comfort and a less stressful listening environment for the older adult population. <B>Geriatr Gerontol Int 2018; 18: 1603–1608</B>.</P>

Factors Influencing the Korean Version of the Digit-in-Noise Test

Kim Subin,Kwak Chanbeom,Han Woojae,Seo Jae-Hyun,Oh Yonghee 대한청각학회 2023 Journal of Audiology & Otology Vol.27 No.2

Background and Objectives: The digits-in-noise (DIN) test was developed as a simple and time-efficient hearing-in-noise test worldwide. The Korean version of the DIN (K-DIN) test was previously validated for both normal-hearing and hearing-impaired listeners. This study aimed to explore the factors influencing the outcomes of the K-DIN test further by analyzing the threshold (representing detection ability) and slope (representing test difficulty) parameters for the psychometric curve fit.Subjects and Methods: In total, 35 young adults with normal hearing participated in the K-DIN test under the following four experimental conditions: 1) background noise (digit-shaped vs. pink noise); 2) gender of the speaker (male vs. female); 3) ear side (right vs. left); and 4) digit presentation levels (55, 65, 75, and 85 dB). The digits were presented using the method of constant stimuli procedure. Participant responses to the stimulus trials were used to fit a psychometric function, and the threshold and slope parameters were estimated according to pre-determined criteria. The accuracy of fit performance was determined using the root-mean-square error calculation.Results: The listener’s digit detection ability (threshold) was slightly better with pink noise than with digit-shaped noise, with similar test difficulties (slopes) across the digits. Gender and the tested ear side influenced neither the detection ability nor the task difficulty. Additionally, lower presentation levels (55 and 65 dB) elicited better thresholds than the higher presentation levels (75 and 85 dB); however, the test difficulty varied slightly across the presentation levels.Conclusions: The K-DIN test can be influenced by stimulus factors. Continued research is warranted to understand the accuracy and reliability of the test better, especially for its use as a promising clinical measure.

Update on Bone-Conduction Auditory Brainstem Responses: A Review

Seo, Young Joon,Kwak, Chanbeom,Kim, Saea,Park, Yoon Ah,Park, Kyoung Ho,Han, Woojae The Korean Audiological Society and Korean Otologi 2018 Journal of Audiology & Otology Vol.22 No.2

<P>Auditory brainstem responses (ABR) have been used as a powerful and the most common objective tool to evaluate hearing sensitivity and to diagnose the types of hearing loss and neurological disorders, through the auditory peripheral pathway to a central level of the brainstem, since 1971. Although bone-conduction (BC) ABR could be an alternative to air-conduction (AC) ABR, as the former overcomes some limitations of the latter, the majority of clinicians rarely utilize it due to a lack of knowledge and no routine test administration. This review presents the weaknesses of AC ABR that apply to all clinical population, and discusses the development of BC ABR. The optimal placements of bone oscillators to obtain favorable clinical outcomes in infants, children, and adults, and the appropriate stimuli for BC ABR are examined. While providing absolute thresholds and latencies of BC ABR based on previous studies compared to AC ABR, this review includes clinical data of infants and young children with both normal hearing in terms of maturation, and with pathology such as congenital external auditory canal atresia. We recommend the future clinical application of BC ABR for candidacy as well as for patients with BC hearing implants.</P>

소음성 난청의 효율적인 예방을 위한 첨도 측정법의 이해

유성화(Sunghwa You),곽찬범(Chanbeom Kwak),김세아(Saea Kim),이장원(Jangwon Lee),정승엽(Seungyeop Jeong),이은성(Eunsung Lee),송현욱(Hyunwook Song),Nour Alsabbagh,한우재(Woojae Han) 한국청각언어재활학회 2018 Audiology and Speech Research Vol.14 No.3

Purpose: In general, energy metrics, i.e., LAeq 8 hours, have been applied as a risk indicator of noise exposure. However, there are some limitations of LAeq measurement since it considers only the amount of average energy of noise and is not appropriate for measuring the complex noise. In light of this, the kurtosis metrics have been introduced by many contemporary researchers to be applied as an alternative measure. Methods: In the main body, we introduced the weakness of current noise exposure criteria, compared between Gaussian and non-Gaussian noise, briefly explained the concepts of kurtosis metrics, and scrutinized more applications of the kurtosis metrics by summarizing previous 7 research papers. Results: Compare to the Gaussian noise, the non-Gaussian noise has been found to have stronger cochlear damage effects on the outer and inner hair cells and led to permanent hearing loss in the higher frequencies. Noise exposure trauma levels were dramatically increased as the kurtosis levels increased. Although kurtosis metrics are a good indicator or measure, it still need to be adjusted in terms of frequency-specificity. Conclusion: Since the kurtosis metrics are not implemented in Korea, especially in the industrial field, we need to develop a new measurement approach using the kurtosis metrics on workers and then provide scientific based criteria for effectively preventing their potential risk of developing noise-induced hearing loss.

조선시대(1392~1910)의 산불정책에 관한 연구

김동현,강영호,김찬범,Kim. Donghyun,Kang. Youngho,Kim. Chanbeom 한국방재학회 2012 한국방재학회논문집 Vol.12 No.6

본 연구는 우리나라의 주요 역사기록서 분석을 통해 조선시대 518년 동안 태조~순조까지 27대 임금이 교체되면서 왕조별로 산불정책 집행에 대한 기록을 고찰하였다. 연구에 활용된 역사서로서는 조선왕조실록, 승정원일기, 대전회통, 고려사절요, 비변사등록, 신보수교집록, 수교집록, 국역증보문헌비고, 경국대전, 황해도연해금송사목, 제도송금사목, 대전속록, 금조절목이문으로 산불정책이 기록된 문헌을 조사, 분석하였다. 역사기록서 문헌에 기록된 산불정책 내용으로는 일반산림에서의 산불정책, 금산과 봉산, 도성 숲에서의 산불정책, 왕실가의 분묘, 종묘, 태실에서 산불정책, 강무장등 사냥터와 사옹원 군기시 시장(柴場)에서의 산불정책, 산불피해지역 백성을 위한 어사 파견 구휼정책, 사고와 사찰에서의 산불정책, 봉수대 등 국토방위를 위한 산불정책, 병충해 구제를 위한 입화 및 입화단속정책이 포함되어 있다. 조선시대 역사기록서를 분석한 결과 조선시대 산불정책은 크게 산불예방목적과 민생안정목적 정책으로 구분할 수 있었다. 결론적으로 조선시대에도 산불의 심각성으로 인해 조정 및 지방에서 여러 산불예방정책과 산불 피해로 인한 민생안정정책이 시행되었다. 또한 산불예방정책 중 산림내 주요시설물을 관리하는 방법이 포함되어 있다. This study surveyed historical records on forest fire polcis during Joseon Dynasty`s 518 years (1392~1910) in being and analyzed the Annals of Joseon Dynasty(朝鮮王朝實錄), The daily records of royal secretariat of Joseon dynasty(承政院日記), Daejonhoetong(大典會通), Koryosachulyo(高麗史節要), Bibyeonsadeungnok(備邊司謄錄), Shinbo Sugyo Jibrok(新補受敎輯錄), Sugyo Jibrok(受敎輯錄), Chungbo munheon bigo(增補文獻備考), Kyeonggukdaejeon(經國大典), Hwanghaedoyeonhaekumsongsamok(黃海 道沿海禁松節目), Jedosongkumsamok(諸道松禁事目), Taezonsokrok(大典續錄), Kumjojeolmokimun(禁條節目移文). Notes recorded in the history of literature wildfire policy is included such as general forest policy, Kumsan(禁山) and Bongsan(封山), citadel in the forest fire policy, Jongmyo(Royal tomb) Shrine of forest fire policy, hunting ground, salvage, defence, pest extermination. In conclusion, forest policy of Joseon Dynast was performed wildfire prevention policy and livelihood stabilization policy. In addition, forest fire prevention policies and how to manage in the major facilities are included.

Effects of Natural Versus Synthetic Consonant and Vowel Stimuli on Cortical Auditory-Evoked Potential

Song Hyunwook,Jeon Seungik,Shin Yerim,한우재,Kim Saea,Kwak Chanbeom,Lee Eunsung,Kim Jinsook 대한청각학회 2022 Journal of Audiology & Otology Vol.26 No.2

Background and Objectives: Natural and synthetic speech signals effectively stimulate cortical auditory evoked potential (CAEP). This study aimed to select the speech materials for CAEP and identify CAEP waveforms according to gender of speaker (GS) and gender of listener (GL).Subjects and Methods: Two experiments including a comparison of natural and synthetic stimuli and CAEP measurement were performed of 21 young announcers and 40 young adults. Plosive /g/ and /b/ and aspirated plosive /k/ and /p/ were combined to /a/. Six bisyllables–/ga/-/ka/, /ga/-/ba/, /ga/-/pa/, /ka/-/ba/, /ka/-/pa/, and /ba/-/pa/–were formulated as tentative forwarding and backwarding orders. In the natural and synthetic stimulation mode (SM) according to GS, /ka/ and /pa/ were selected through the first experiment used for CAEP measurement.Results: The correction rate differences were largest (74%) at /ka/-/ pa/ and /pa/-/ka/; thus, they were selected as stimulation materals for CAEP measurement. The SM showed shorter latency with P2 and N1-P2 with natural stimulation and N2 with synthetic stimulation. The P2 amplitude was larger with natural stimulation. The SD showed significantly larger amplitude for P2 and N1-P2 with /pa/. The GS showed shorter latency for P2, N2, and N1-P2 and larger amplitude for N2 with female speakers. The GL showed shorter latency for N2 and N1-P2 and larger amplitude for N2 with female listeners.Conclusions: Although several variables showed significance for N2, P2, and N1-P2, P1 and N1 did not show any significance for any variables. N2 and P2 of CAEP seemed affected by endogenous factors.