Kyoungwon Lee

Derivations of the band-importance function: A cross-procedure comparison

The purpose of this study was to compare band-importance functions (BIFs) derived by two different procedures. Intelligibility data from native speakers of Korean were used. BIFs were derived using an established procedure reported by Studebaker and Sherbecoe [J. Speech Lang. Hear. Res. 34, 427-438 (1991)] and by a recently published method reported by Kates [J. Acoust. Soc. Am. 134(5), EL459-EL464 (2013)]. The BIFs produced by the two different procedures were similar. These results indicate that the BIF calculation procedure by Kates is accurate for sentences as well as for the monosyllables used in its derivation.

Reference sound pressure level for Korean speech audiometry

Abstract Objective: The purpose of this study was to examine the reference sound pressure level (RSPL) for Korean speech audiometry which was defined as the reference speech recognition threshold level (RSRTL) equivalent to 0 dB HL at the audiometer. Study sample: Subjects consisted of 20 adults (40 ears) with normal hearing sensitivity. Design: Puretone thresholds (PTs) were obtained in 2 dB steps at each octave band. The newly developed Korean bisyllabic words were used to establish the speech recognition thresholds (SRTs). The SRT was the level at 50% correct responses based on the psychometric function performed from -8 dB HL (12 dB SPL) up to the level at or above 90% correct responses in 2 dB steps. Results Conclusions: The mean SRT was 23.44 dB SPL for sets comprised of 36 Korean bisyllabic words. Thus, the difference between English and Korean RSRTLs was about 3.44 dB. We recommend further study to recalculate the RSRTL for Korean speech audiometry with more subjects. Sumario Objetivo: El propósito de este estudio fue examinar el nivel de presión sonora de referencia (RSPL) para la logoaudiometría en coreano, que fue definido como el nivel umbral de referencia para el reconocimiento del lenguaje (RSRTL), equivalente a 0 dB HL en el audiómetro. Muestra Del Estudio: Los sujetos de estudio fueron 20 adultos (40 oídos) con sensibilidad auditiva normal. Diseño: Se obtuvieron umbrales tonales puros (PT) en pasos de 2 dB para cada banda de octava. Se usaron las recientemente desarrolladas palabras bisilábicas coreanas para establecer los umbrales de reconocimiento del lenguaje (SRT). El SRT fue el nivel donde se obtuvo un 50% de respuestas correctas, con base en la función psicométrica realizada desde −8 dB HL (12 dB SPL) hasta un nivel ubicado donde se logra un 90% o mayor de respuestas correctas, en pasos de 2 dB. Resultados Y Conclusiones: La mediana del SRT fue de 23.44 dB SPL para listas de 36 palabras bisilábicas coreanas. Por tanto, la diferencia entre el SRT en coreano y en inglés fue de 3.44 dB. Recomendamos estudios adicionales para recalcular el RSRTL para la logoaudiometría en coreano con más sujetos.

Effects on Word and Sentence Recognition by Auditory Training Using Environmental Sound for Elderly Hearing Impaired

다양한 이유로 청각손실이 발생하면 보청기의 착용, 인공와 우 시술 등을 통하여 난청인의 의사소통능력의 개선을 기대할 수 있다. 청력손실의 정도가 고심도 이상이거나 너무 낮은 단어 인지도(word recognition score, WRS)를 나타내는 경우, 그리 고 외이가 기형적인 형태가 아니라면 기도 보청기(air conduction hearing aid)의 착용을 통해 난청인의 생심리사회적(biopsychosocial)인 핸디캡을 개선할 수 있다. 그러나 대부분의 난 청인들은 보청기를 착용한 후에도 주변의 다양한 소리를 비롯 하여 회화음을 예전처럼 들을 수 없어서 실망을 하며, 이러한 이유로 보청기를 구입하고도 착용을 거부하거나 실패하는 비 율이 높게 나타나고 있다(Koo et al., 2006). 보청기 착용인에게 최적의 음질을 제공하고 어음의 청취능력을 개선하기 위해서는 2-cc 커플러, 실이측정, 기능이득(functional gain), 음장에서의 어음 인지도 측정 등 다양한 보청기 적합의 확인(verification) 을 통하여 보청기의 이득, 최대 출력 등 전기음향적인 요소의 지속적인 조절이 필요하다. 그리고 보청기를 최적으로 조절하 였음에도 불구하고 보청기 착용인이 일상생활에서의 대화능력 이 저하된다면 청능훈련을 시도할 필요가 있다(Humes et al., 2014). 청능훈련은 여러 가지 이유로 어음인지도가 저하된 난청인의 의사소통능력을 극대화할 수 있는 방법 중의 하나다. Brouns et al.(2011)은 소리에 대한 지각은 뇌의 신경가소성에 기초하며, Morais et al.(2015)은 보청기, 인공와우 등 증폭기의 사용만으 로 어음을 인지하는 데 한계가 있기 때문에 난청인이 보청기, 인 공와우 등의 증폭기를 착용한 후 반복적으로 듣는 연습을 통해 보다 개선된 의사소통능력을 향상시킬 수 있다고 보고하였다. Effects on Word and Sentence Recognition by Auditory Training Using Environmental Sound for Elderly Hearing Impaired Jeehee Kim, Kyoungwon Lee Sungnam Joongwon Starkey Hearing Aid Center, Sungnam, Korea Department of Audiology, Hallym University of Graduate Studies, Seoul, Korea

The Gaps between Knowing and Doing in Hearing Aid Fitting Management

Evidence based practice has become an important aspect in many healthcare provisions to improve patient outcomes. Investigating the gaps between knowing and doing in audiology practice will provide future directions for successful service delivery. The purpose of this study was to explore “know-do” gaps related to professional awareness and attitude in hearing aid fitting management (HAFM) by analyzing data of a questionnaire. It consisted of 22 questions focusing on 11 HAFM components. Each component had two sub-questions involving levels of the importance and practice for HAFM. Respondents answered each question based on subjective judgments for their own hearing aid fitting services with a Visual Analogue Scale. A total of 51 responses from hearing care professionals were collected and the scores for knowing and doing were compared. The results showed overall high scores in doing and knowing responses; however, there were significant “know-do” gaps demonstrating higher knowing scores than doing scores across all HAFM components. The largest “know-do” gaps were observed in three components mostly implemented during follow-up sessions which indicate the need to improve their corresponding services and practical guidelines emphasizing the follow-up services.

Comparisons of Sentence Recognition Scores and Preferences according to Compression Types in a Multi-Channel Hearing Aid

현재 보청기의 기술은 디지털 기술의 접목으로 난청인의 의 사소통 능력의 개선에 많은 도움을 주고 있다. 최근까지의 보청 기의 기술을 간략히 살펴보면 채널 수의 증가, 음향피드백, 폐 쇄효과, 잡음 등의 효과적인 제어, 난청인이 듣기 힘든 고주파 수 대역의 정보를 잔존청력이 남아 있는 주파수 대역에서 듣게 하는 주파수하강(frequency lowering), 양측에 착용한 보청기 의 정보를 서로 교환하여 신호를 처리하는 양이통신 등이 있다 (Bohnert et al., 2010; Glista et al., 2009; Lee, 2014). 그러나 보 청기의 기술이 발전했음에도 불구하고 내이의 손상으로 인해 역동범위가 감소한 감각신경성난청인에게 보청기를 적합할 경 우에는 상기의 보청기 기술과 아울러 비선형의 증폭 특성 및 조절 방식에 대한 이해가 필요하다.현재 보청기의 기술은 디지털 기술의 접목으로 난청인의 의 사소통 능력의 개선에 많은 도움을 주고 있다. 최근까지의 보청 기의 기술을 간략히 살펴보면 채널 수의 증가, 음향피드백, 폐 쇄효과, 잡음 등의 효과적인 제어, 난청인이 듣기 힘든 고주파 수 대역의 정보를 잔존청력이 남아 있는 주파수 대역에서 듣게 하는 주파수하강(frequency lowering), 양측에 착용한 보청기 의 정보를 서로 교환하여 신호를 처리하는 양이통신 등이 있다 (Bohnert et al., 2010; Glista et al., 2009; Lee, 2014). 그러나 보 청기의 기술이 발전했음에도 불구하고 내이의 손상으로 인해 역동범위가 감소한 감각신경성난청인에게 보청기를 적합할 경 우에는 상기의 보청기 기술과 아울러 비선형의 증폭 특성 및 조절 방식에 대한 이해가 필요하다. 비선형 보청기의 전기음향적 조절 파라미터는 이득, 최대출력 (maximum power output) 또는 OSPL90 (output sound pressure level for 90 dB input sound pressure level), 압축비율 (compression ratio, CR), 압축역치(compression threshold, Comparisons of Sentence Recognition Scores and Preferences according to Compression Types in a Multi-Channel Hearing Aid Suyeon Shin, Kyoungwon Lee SSY Aural Rehabilitation Center, Daejeon, Korea Department of Audiology, Hallym University of Graduate Studies, Seoul, Korea

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

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 (KS-SL-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.

Review in Hearing Aid Prescription Methods and Its Considerations in Korean Studies

Review in Hearing Aid Prescription Methods and Its Considerations in Korean Studies Kyoung-Won Lee and Jin-Sook Kim Department of Audiology, Hallym Institute of Advanced International Studies, Seoul, Korea Department of Speech Pathology and Audiology, College of Natural Science, Hallym University, Chuncheon, Korea In order to develop Korean hearing aid prescription method, this study examined features of gain, frequency response curves, saturation sound pressure level 90 (SSPL90), output sound pressure level 90 (OSPL90), compression threshold (CT), and compression ratio (CR), and attack time (AT)/release time (RT) of linear and non-linear hearing aids. Futhermore, Korean studies related to characteristics of physique, psychoacoustics, speech and language effects were summarized. Following review and summarization, several suggestions for Korean hearing aid prescription method were also presented. Results showed that there were some differences in gain and frequency response curves, SSPL90 or OSPL90 among each hearing aid prescription methods despite the similarity of race and languages. Several factors were considered for calculating CT, CR, AT and RT, dynamic range, speech audibility, signal-to-noise ratio and tonal quality. However there were no agreements on the calculation of those parameters because several preferred factors were not identical among hearing impaired people. Korean hearing aid prescription method is not developed yet. Currently when the hearing aids are imported, fitting softwares with hearing prescription methods come without consideration of differences in acoustic characteristics of Korean language. In conclusion, we strongly suggest that various fundamental studies should be explored for the effective method for aural rehabilitation in Korean hearing impaired listeners.