인공와우 사용자의 심리음향적 음질평가 예비연구

방정화,오수희 한국음향학회 2022 韓國音響學會誌 Vol.41 No.1

Sound quality evaluation is one of the psychoacoustic methods to measure subjective judgements for sound color. The purpose of this study is to investigate sound quality benefits of bimodal users by comparing sound quality scores between bimodal hearing condition and unilateral cochlear implant(CI) condition as a preliminary study. Thirteen bimodal users and seven unilateral CI users were participated in this study. Audiologists performed pure tone and speech audiometry and measured functional gain and real-ear insertion gain. Subjective assessment of sound quality was followed with four sounds including violin sound, male and female voices, and refrigerator noise. Participants judged the sound quality with six sound quality index. Bimodal users showed mean 0.8 points more sound quality improvements in bimodal condition than unilateral CI condition. Group comparison between bimodal and unilateral CI users showed no differences. A follow-up study of sound quality tools and methods should be considered to evaluate subjective bimodal benefits of cochlear implant users. 음질평가는 물리적 음향 자극에 대해 주관적으로 지각되는 음색을 평가한다는 측면에서 심리음향학적 측정과 관련이 있다. 본 논문은 인공와우 사용자의 음질평가를 위한 예비연구로서 바이모달 인공와우 사용자를 대상으로음질평가를 시행하고 인공와우만 착용했을 때와 바이모달을 착용했을 때의 음질평가 차이를 파악하고자 하였다. 총13명의 바이모달 인공와우 사용자와 7명의 편측 인공와우 사용자가 연구에 참여하였고 순음 및 어음 청력검사, 보청기기능이득과 실이삽입이득을 측정하였다. 음질평가에서는 바이올린소리, 남자와 여자 노래소리, 냉장고 소음의 4개 음향자극을 방음실에서 들려주고 6개 음질평가 항목에 대해 0에서 10까지의 척도로 표시하도록 하였다. 검사결과 바이모달 사용자는 편측 인공와우만 착용했을 때보다 바이모달을 착용했을 때 음질평가 5개 항목에서 0.8점 높았고, 바이모달 사용자와 편측 인공와우 사용자 그룹간 비교에서는 두 그룹 사이에 차이를 보이지 않았다. 주관적 측면의 바이모달 혜택 측정을 위해서 좀 더 체계적인 음질평가 도구와 방법에 대한 후속 연구가 필요할 것으로 생각된다.

음악감상에서의 음질 평가를 위한 한국어 어휘의 의미론적 속성 분석

이은영(Eun Young Lee),유가을(Ga Eul Yoo),이영미(Youngmee Lee) 한국음악치료교육학회 2024 인간행동과 음악연구 Vol.21 No.2

본 연구는 음악감상 시 지각하는 음질(sound quality)을 평가할 때, 어휘를 통한 평가가 음악 유형에 따라 달라지는지 분석하여, 음질 평가 어휘의 의미론적 속성에 대한 기초 자료를 제공하고자 하였다. 평균 9.4년의 전문 훈련을 받은 20-30대의 음악 전공자 31명이 참여하였고, 각 참여자는 성부 수와 악기의 소리 산출 방식(악기군)에 따라 구성된 9개 음악을 듣고 음질을 나타내는 18개 의미 단어 쌍을 평가하였다. 요인 분석을 통해 동일 요인에 영향을 받는 단어들을 그룹화하였고, 다변량 분산 분석을 통해 각 요인 그룹별로 성부 수와 악기군에 따른 차이를 확인하였다. 또한, 유의한 차이를 보이는 의미 단어 세트를 사용해 레이더 차트를 그려 각 음악별 차이를 시각적으로 분석하였다. 연구 결과, 4개 요인이 추출되었으며, ‘부드러운-딱딱한’, ‘둔한-날카로운’, ‘지저분한-정돈된’, ‘낮은-높은’의 단어 쌍이 음악 유형에 따라 유의한 차이를 보였다. 이 4개 단어 쌍을 바탕으로 작성된 레이더 차트는 각 음악에 대한 음질 평가를 구분하는 데 효과적이었다. 이 결과는 한국어 기반 음질 평가 어휘 개발 시, 국외 연구에서 보고된 범주와는 다른 구조의 체계가 필요하며, 언어적ㆍ문화적 요인의 반영이 중요함을 시사한다. 또한, 교차 감각 대응(cross-modal correspondence)에 기반한 어휘 범주 중에서도 음향적 속성에 민감한 범주가 존재함을 확인하였다. 본 연구는 언어적ㆍ문화적 속성과 더불어 음질에 영향을 미치는 음악 요인을 반영할 수 있는 음질 평가 어휘 개발에 필요한 기술자료를 제공할 것으로 기대된다. This study aims to classify the semantic words commonly used to evaluate sound quality and to analyze their differences in reflecting the level of musical stimuli. Participants were thirty-one music majors in their 20s and 30s, with an average of 9.4 years of professional training. Each participant listened to nine pieces of music with variations in texture and instrument type and evaluated them using 18 pairs of semantic words describing sound quality. A factor analysis was conducted to group words influenced by the same latent factor, and a multivariate ANOVA determined the differences in ratings based on texture and instrument type. Radar charts were also drawn based on the identified sets of semantic words. The results showed that four factors were identified, and the word pairs ‘soft-hard,’ ‘dull-sharp,’ ‘muddy-clean’ and ‘low-high’ showed significant differences based on the level of musical stimuli. The radar charts effectively distinguished the sound quality evaluations for each music. These results indicate that developing Korean semantic words for sound quality evaluation requires a structure different from the previous categories used in Western countries and that linguistic and cultural factors are crucial. This study will provide foundational data for developing a verbal sound quality evaluation framework suited to the Korean context, while reflecting acoustic attributes in music listening.

냉장고 기계실의 고주파 소음 특성 분석을 통한 음질 개선

장준영,김태훈,탁언수,정의봉,안세진 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.5

This paper provides an analysis of the characteristics of the noise of components that affect the sound quality of oil-less refrigerators and suggests ways to effectively improve the sound quality. As the sound quality of refrigerators is determined by the characteristics of the various components and the path through which the noise is transferred, it is necessary to first analyze the characteristics of the noise generated by the components. Therefore, after measuring the noise of each part, we conducted a contribution analysis of the sound quality of each noise source. As a result, the oil-less compressor was found to be the dominant part of the sound quality of the refrigerator, while the high-frequency noise of the compressor is the main cause of poor sound quality. Then, to improve the sound quality by reducing the high-frequency noise of the compressor, we changed the transfer path of the noise using sound-absorbing and -insulating material and predicted the effect of the sound quality through a pressure transmissibility test. As a result of verification from actual operation, the sound quality of the refrigerator was improved most by the reduction of the sharpness and criteria of declination when the absorbent was attached to the surrounding walls of the compressor. Finally, the overall SPL decreased by 2.95dBA, and the sound quality score was improved by 1.83.

SBR(Seat Belt Reminder)Sound의 가청도와 음질에 대한 고찰

김준우(Junwoo Kim),황인선(Inseon Hwang),최은수(Eunsoo Choi) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Now a days. the emotional quality of vehicle is a very important evaluation standard. SBR sound needs not only emotional quality but also safety performance. In this thesis, we considered two important factors, which are audibility and sound quality as a standard of a suitable SBR sound and gave guide line to make SBR sound according to frequency and amplitude which are main factors of audibility and sound quality. When the frequency of SBR sound is low, the suitability of SBR sound follows the trend of audibility. On the contrary, when the frequency of SBR sound is high, the suitability follows the trend of frequency preference. Therefore, ideal SBR sound is need to have at least 4㏈ audibility and the frequency of about 1000㎐. In this thesis, we considered only frequency and amplitude to determine good SBR sound. From now on, the pattern. harmonize chime. etc. the factors which influence sound quality will be studied.

승용차 브랜드 사운드를 위한 이차원 음질 인덱스 개발

조병옥(Jo, Byoung-Ok),박동철(Park, Dong-Chul),이민섭(Lee, Min-Sub),정승균(Jung, Seung-Gyoon),이상권(Lee, Sang-Kwon) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.5

In automotive engineering, the brand sound is one of the important advantage strategies in a car company. For the design of brand sound, the selection of descriptive word for a car sound is one of major works in automotive sound quality research. In this paper, booming and rumbling sound, which are professional words used by sound and vibration engineers are used for the design of brand sound. We employed sound quality metrics, which are used in the psychoacoustics. By most research results, the relationship between subjective evaluations and sound quality metrics has nonlinear characteristics. In order to correlate these subjective evaluations with sound quality metrics, the artificial neural network technology has been applied to two-dimensional sound quality index for a passenger car. These indexes are used for 46 passenger cars, which are samples of the famous cars around the world. Also a preference evaluation for car sound was carried out by sound and vibration engineers. We coupled this preference with booming and rumbling sounds by using artificial neural network. In future, the two dimensional sound and preference index will be very useful to develop brand sound in passenger cars.

감성 품질 향상을 위한 자동차 Horn의 선호 음질에 관한 연구 및 음질 요소 개발

강희수(Hee-Su Kang),이상권(Sang-Kwon Lee),신태진(Tae-Jin Shin),정기웅(Ki-Woong Jung),박동철(Dong-Chul Park) 한국소음진동공학회 2015 한국소음진동공학회 논문집 Vol.25 No.3

In this study, there is an investigation about the sound quality of automotive horn that attached to luxury sedans. In order to define a questionnaire of horn sound quality the factor analysis is conducted. Ten automotive horns are selected for this research and ten passenger cars(nine is luxury sedan and one economy class car). Luxury is used for the questionnaire as an attribute for the sound quality of car horn. The interior noises for ten test cars are recorded and used for the subjective analysis of car horn sound. In the paper, new sound metric for the car horn sound is presented. The new sound metric is used for the objective sound index for the prediction of subjective sound quality of car horn.

차량용 전동 롤러 블라인드의 고급감 음질지수 개발

성원찬(Weonchan Sung),조현호(Hyeonho Jo),강연준(Yeon June Kang),김성현(Seonghyeon Kim),박동철(Dongchul Park) 한국소음진동공학회 2015 한국소음진동공학회 논문집 Vol.25 No.5

Sounds of electrically powered vehicle components such as window lift system, roller blind, etc., are required to be more comfortable and not to irritate the people emotionally. In this paper, a study was conducted to identify the significant sound quality metric and compose the luxuriousness sound quality index of electrically powered vehicle roller blind which is part of vehicle sunroof system. Before conducting subjective evaluation, sound characteristics of roller blind was analyzed and set the target operating sound for subjective evaluation. Thus, transfer sound of roller blind which has the characteristics of sound modulation was used for subjective evaluation. Multiple linear regression analysis was carried out by chosen Zwickers metrics which are pointed by comments of jurors. Loudness and sharpness related metrics are prime metrics in luxuriousness sound quality index we composed. Also, effect of roller blind assay when it is attached to real vehicle was identified to evaluate the validity of index.

타이어 종류에 따른 차량 실내 소음의 Mahalanobis Distance 를 이용한 음질인덱스 구축

정재은(Jae-Eun Jeong),양인형(In-Hyung Yang),박군동(Goon-Dong Park),이유엽(You-Yub Lee),오재응(Jae-Eung Oh) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.12

사람이 소리를 듣는 것은 다분히 감정적이고 주관적으로 이루어진다. 따라서 소음 측정의 척도로 주로 사용되는 dB(A)와 같은 청감을 고려한 수치로 표현하기 어렵기 때문에 때와 장소, 차량에 따라 주관적이고 사람의 감정에 맞는 주관적 척도가 요구된다. 즉, 평가하고자 하는 음질인자 항목들은 독립적 관계가 아닌 서로 상관관계의 특성을 고려하여 음질 평가를 수행해야 한다. 그러므로 인간의 청감에 가깝고 정확한 음질 평가를 위해서는 음질인자 별 다변량 분석이 필요하다. 본 연구에서는 차량주행 소음을 대상으로 특성인자간 상관관계를 고려해 시스템을 분석할 수 있는 마할라노비스 거리(Mahalanobis distance,MD)를 통해 음질 인덱스를 구축하고자 한다. The reduction of vehicle interior noise has been the main interest of NVH engineers. The driver’s perception of the vehicle noise is strongly affected by the psychoacoustic characteristics of the noise and the SPL. The existing methods to evaluate the SQ for vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of subjective SQ values by neural network. However, these methods strongly depend on jury tests, this leads to difficulties. To reduce the important of the jury tests, we suggest a new method using the Mahalanobis distance for SQ evaluation. And, the optimal characteristic values that influenced the results of sound quality evaluation on the basis by main effect. Finally, we developed a new method based on the MD method to evaluate sound quality. The result of noise evaluation revealed that the sound quality could be well improved by changing the structural characteristics of the vehicle.

진동 분석 및 합성곱 신경망 기반 기계 고장 진단

정광훈,김완승,김나래,박준홍 한국비파괴검사학회 2022 한국비파괴검사학회지 Vol.42 No.6

We developed an intuitive fault diagnosis method related to human auditory characteristics by applying sound quality parameters to the vibration signal. Abnormal noise was generated from a fault in a machine, and the operator used this noise to detect the abnormal condition. Although these acoustic characteristics differ with the fault conditions, diagnosing various fault conditions is limited by the auditory characteristics of the operator. The sound quality parameters represent the human auditory characteristics as physical quantities. However, the sound signal is vulnerable to various external noises generated in the environment. The vibration signal is robust to various external noises generated in the process, and the sound signal and vibration signal have a high correlation. Therefore, the vibration signals of the normal condition and various fault conditions were measured using a laser Doppler vibrometer (LDV). The sound quality parameters were applied to the vibration signal, and the characteristics of the sound quality parameters for each machine condition were analyzed. A convolutional neural network (CNN) was used to extract important features from the sound quality parameters for pattern recognition. The classified features facilitated a clear demarcation between the conditions of the machine. The classification performance of the proposed method was verified through comparison with other classification models. 진동신호에 음질인자를 적용하여 사람의 청감 특성과 연관된 직관적인 고장 진단 방법론을 제안한다. 기계의 고장으로부터 비정상적인 소음이 발생하며, 이러한 소음을 이용하여 작업자들은 기계의 이상 상태를 탐지한다. 음향 특성은 기계의 다양한 고장 상태에 따라 상이하지만, 작업자의 청감 특성에만 의존하여 여러 고장 상태의 진단에는 한계가 있다. 음질인자는 사람의 청감 특성을 물리량으로 나타낸 지표이다. 하지만, 음향신호는 외부에서 발생하는 다양한 외부 소음에 취약하다. 진동신호는 외부 소음에 매우 강건한 특성을 지니고 있으며 음향신호와 진동신호는 매우 큰 상관성을 가진다. 따라서 전자레인지의 정상 상태 및 여러 고장 상태들에 대한 진동신호를 laser Doppler vibrometer (LDV)로 측정하였다. 진동신호에 음질인자가 적용되었으며, 각 기계의 상태에 대한 음질인자의 특성들이 분석되었다. 합성곱 신경망(convolutional neural network, CNN)은 패턴 인식을 위해 음질인자에서 중요한 특징을 추출하였다. 분류된 특징들은 각 기계의 상태들 간에 경계를 뚜렷하게 하였다. 제안한 방법의 분류 성능은 다른 분류 모델들과의 비교를 통해 검증되었다.

차량 실내공간의 가속 시 엔진음 음질 향상을 위한 실시간 능동음향증강 제어 구현

이영섭(Young-Sup Lee),김제관(Jeakwan Kim),유석훈(Seokhoon Ryu),김성현(Seonghyeon Kim),박동철(Dong Chul Park) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.2

In this study, a concept of active sound enrichment (ASE) control system was implemented and demonstrated for improving engine sound quality inside the cabin of a passenger car during acceleration. Unlike the active noise control cancels the noise for disturbance rejection, the ASE adds additional sound to the noise for tracking control. This approach requires a new algorithm to provide additional artificial sound to the original engine sound using active control strategy to achieve a target sound profile, which is predefined to satisfy required interior sound quality. The ASE algorithm was implemented in a digital controller dSPACE DS1401 and real-time control experiment was accomplished in an actual car. The ASE control results show that the actively enriched sound of each engine order against RPM tracks the target profiles precisely and quickly and improves the discontinuity, the level ratios and the sound pressure level of each engine order. Thus it is anticipated the ASE system can be applied for the improvement of the engine sound quality inside the cabin during acceleration.