• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.323-327
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• 2007

In this paper, objectively quantified consonance of complex sound is proposed as a new psychoacoustical parameter. Proposing algorithm quantifies consonance of complex sound after applying psycho acoustical models which are parts of human perception such as masking effect, equal loudness contour, and critical band. To verify proposing algorithm, experiments with 10 car horn signals which have different complex sound were performed. The experiments show cross correlation of 0.95 between objectively quantified consonance by proposing algorithm and subjectively assessed consonance by listening tests. Considering the fact that there are few psychoacoustical parameter except Zwicker parameter, proposing algorithm will help to quantify psychoacoustical effect of complex sounds objectively.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.545-546
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• 2004

서브밴드 분리에 의한 에코확산 오디오 워터마킹법은 호스트 신호를 특정 주파수 대역으로 분리하고, MPEG 심리음향 모델을 이용하여 각 대역별로 삽입되는 워터마크의 파워를 파라미터 설정 함수에 의하여 설정한다. 여기서, 본 방법의 강인성과 비지각성을 좌우하는 것은 파라미터 설정 함수가 된다. 따라서, 본 연구에서는 최대의 강인성과 최소의 음질 열화를 구현하기 위하여 청취실험을 실시하여 최적의 파라미터 설정 함수 설정방법에 대한 검토를 수행하였다.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.369-379
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• 2016

This paper deals with an efficient method for skipping inter-channel phase differences (IPD) in the MPEG surround of the unified speech and audio coding (USAC). Based on the psycho-acoustic sensitivity on the IPD, we estimate a threshold on IPD, below which we can not notice degradation in spatial cue. We propose an IPD skip method, in which any IPDs within the threshold are set to zero and are not transmitted. The proposed IPD skip method gives about 38% savings in terms of bit amount for IPD. Nevertheless, in the MUSHRA test, the proposed method does not show any noticeable degradation in the decoded audio quality.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.189-192
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• 2000

본 논문에서는 청각 장애인의 보다 향상된 보청 환경을 조성하고자 청각손실을 심리음향 모델을 적용하여 감음 신경성 난청을 보정하는 알고리즘을 제안한다. 제안한 알고리즘에서는 난청의 유형은 내이에서부터 중추 뇌에 걸친 감음계와 신경계의 장애에서 비롯되는 감음신경성 난청(sensorineural hearing loss)으로 주파수 영역상에서 MTH(minimum hearing threshold)가 균일하지 않게 상승하게되어 가청영역이 좁아지는 문제점을 해결하기 위한 방법으로 각각의 주파수 밴드마다 멀티밴드 압축 알고리즘을 적용하였다. 그러나 이 경우 각각의 주파수 밴드에 따른 서로 다른 가청 영역의 영향에 의한 변형된 스펙트럼 모양으로 인해 spectral contrast reduction과 변형된 마스킹 특성으로 인해 음성 변별력에 제한을 가하게 된다. 이것은 주변 주파수 성분들에 의한 마스킹 효과에 의한 것으로, 신호에 대한 난청인이 느끼는 지각 영역(perceptual domain)에서의 해석과 심리음향 모델 파라미터를 통한 보청기의 개발이 이루어져야 하며, 본 논문에서 그 알고리즘을 적용하였다.

• Science of Emotion and Sensibility
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• v.15 no.2
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• pp.201-208
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• 2012

The objectives of this study were to investigate the psychoacoustic properties of PTFE(Poly tetra Fluoroethylene) laminated vapor permeable water repellent fabrics which are frequently used for sportswear, to examine the relationship among fabrics' basic characteristics, mechanical properties and the psychoacoustic properties, and finally to propose the predicting model to minimize the psychoacoustic fabric sound. A total of 8 specimens' frictional sound were recorded and Zwicker's psychoacoustic parameters such as loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z) were calculated using the Sound Quality Program. Mechanical properties of specimens were measured by KES-FB system. Loudness(Z) of specimen D-1 was the highest, which means the rustling sound of the specimen D-1 was the most noisy. Statistically significant difference among film type was observed only in loudness(Z) for fabric sound. Based on ANOVA and post-hoc test, specimens were classified into less loud PTFE film group (groupI) and loud PTFE film group (groupII). Loudness(Z) was higher when staple yarn was used compared when filament yarn was used. According to the correlation between the mechanical properties of fabrics and loudness(Z) in groupI, the shear properties, compression properties and weight showed positive correlation with loudness(Z). According to the regression equation predicting loudness(Z) of groupI, the layer variable was chosen. In groupII, variables explaining the loudness(Z) were yarn types and shear hysteresis(2HG5).

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.9
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• pp.1593-1602
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• 2001

본 연구는 스포츠 아우터웨어용 나일론 직물의 소리에 대한 주관적 감각과 이에 관련된 객관적 측정치를 규명하기 위하여, 서로 다른 8종의 나일론 직물의 소리의 스펙트럼 파형을 고찰하였으며, 소리 파라미터로 총음압(level pressure of total sound, LPT),세 가지 AR (autoregressive)계수, Zwicker의 심리음향학적 모델에 따른 크기(Z)와 날카로움(Z)를 계산하였고, Kawabata Evaluation System(KES)으로 직물의 물리적 성질을 측정하였다. 주관적 감각 평가를 위하여 피험자에게 녹음된 각 직물소리를 들려주어 7개 소리 감각 (부드러움, 시끄러움, 날카로움, 맑음, 거 침, 높음, 유쾌함)을 의미분별척도로 답하게 한 후, 단계적 선형 회귀식을 이용하여 직물 소리의 주관적 감각에 대한 예측 모델을 제시하였다. 울트라스웨이드를 제외한 태피터 나일론 직물들은 스펙트럼 파형 에서 다른 조성 섬유의 직물들보다 음압 값이 높고, 총음압이 60dB 안팎의 값을 보여, 착용자에게 불쾌감을 줄 것으로 예상되었으며, 주관적 감각 평가에서도 소리의 부드러움과 맑음, 유쾌함에서 음의 점수를, 시끄러움과 날카로움, 거침, 높음에서 양의 점수를 얻었다. 주관적 감각의 예측모델에서 총음압은 시끄러움과 거침에 정적 영향을, 유쾌함에 부적 영향을 미쳐서 나일론 직물 소리의 총음압이 50dB 이하일 때 주관적으로 유쾌하게 느껴지는 것으로 나타났다.

• The Journal of the Acoustical Society of Korea
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• v.23 no.6
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• pp.437-445
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• 2004

In this paper. we describe a novel method for transforming audio contents according to user's preference on sound field. Sound field effect technologies. which transform or simulate acoustic environments as user's preference, are very important for enlarging the reality of acoustic scene. However huge amount of computational power is required to process sound field effect in real time. so it is hard to implement this functionality at the portable audio devices such as MP3 player. In this paper, we propose an efficient method for providing sound field effect to audio contents independent of terminal's computational power through processing this functionality at the server using user's sound field preference, which is transfered from terminal side. To describe sound field preference, user can use perceptual acoustic parameters as well as the URI address of room impulse response signal. In addition, a novel fast convolution method is presented to implement a sound field effect engine as a result of convoluting with a room impulse response signal at the realtime application. and verified to be applicable to real-time applications through experiments. To verify the evidence of benefit of proposed method we performed two subjective listening tests about sound field descrimitive ability and preference on sound field processed sounds. The results showed that the proposed sound field preference can be applicable to the public.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.56-66
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• 2001

The spectral subtraction algorithm using a criterion based on the human perception has been recently developed. The speech processed with Virag's algorithm sounds more pleasant to a human listener than those obtained by the classical methods. However, Virag's algorithm requires a robust voice activity detector (VAD). In the ESS (extended spectral subtraction) algorithm without VAD, the residual noise becomes more noticeable as the SNR decrease. In this paper we propose a new speech enhancement method, the combination of Wiener filter and spectral subtraction based on noise masking characteristics in the human auditory system. There is no need of VAD because the noise can be successively updated even during speech activity using Wiener filter. The adjustment of the subtraction parameter based on the masking threshold makes the residual noise inaudible. The proposed method has been compared with conventional spectral subtraction algorithms. Objective and subjective evaluation of the proposed system is performed with several noise types having different time-frequency distributions. The application of objective measures, the study of the speech spectrograms, as well as subjective listening tests, confirm that the enhanced speech with proposed algorithm is more pleasant to a human listener.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.827-827
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• 2009

Complaints against high-speed train interior noise have been increasing as a number of high-speed train passenger grows bigger. It is very difficult to analyze characteristics of high-speed train interior noise using sound pressure level only. It is requested to consider how the public response change for each high-speed train interior noise. This study presents evaluation of the sound quality for interior noise of KTX-II using Zwicker parameters. Characteristic of loudness and sharpness is different between noise samples depending on operation condition. The noise sample that recorded when the high-speed train passed through tunnel section is more louder and sharper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.661-665
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• 2006

This study investigates objective and subjective evaluations of refrigerator noise. To describe the fluctuations like a click, a rapid increase of sound level, a change of pitch, a transition into the stationary and ending phase, the psychoacoustical and autocorrelation function(ACF) parameters have been employed. First, subjective evaluation of the noisiness of 24 kinds of refrigerators was conducted. Then, the relationship between objective measures of the refrigerator noise on perceived noisiness was examined with multiple regression analyses. Sound Quality Indices using the psychoacoustical and ACF parameters were also developed. The important psychoacoustical parameters for evaluating noisiness are loudness and roughness of stationary phase. The relationship between the noisiness and the ACF parameters shows that sound energy ${\Phi}(0)$ and its fluctuations are important. Also, refrigerator sounds that had a fluctuation of pitch were rated as more annoying. The fluctuation of pitch is expressed by ${\tau}_1\;and\;{\Phi}_1$ defined by the delay time and the amplitude of the first peak of the ACF.