Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of the Acoustical Society of Korea
Journal Basic Information
Journal DOI :
The Acoustical Society of Korea
Editor in Chief :
Volume & Issues
Volume 31, Issue 8 - Nov 2012
Volume 31, Issue 7 - Oct 2012
Volume 31, Issue 6 - Aug 2012
Volume 31, Issue 5 - Jul 2012
Volume 31, Issue 4 - May 2012
Volume 31, Issue 3 - Apr 2012
Volume 31, Issue 2 - Feb 2012
Volume 31, Issue 1 - Jan 2012
Selecting the target year
Nasal Place Detection with Acoustic Phonetic Parameters
Lee, Suk-Myung ; Choi, Jeung-Yoon ; Kang, Hong-Goo ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 353~358
DOI : 10.7776/ASK.2012.31.6.353
This paper describes acoustic phonetic parameters for detecting nasal place in a knowledge-based speech recognition system. Initial acoustic phonetic parameters are selected by studying nasal production mechanisms which are radiation of the sound through the nasal cavity. Nasals are produced with differing articulatory configuration which can be classified by measuring acoustic phonetic parameters such as band energy ratio, band energy differences, formants and formant differences. These acoustic phonetic parameters were tested in a classification experiment among labial nasal, alveolar nasal and velar nasal. An overall classification rate of 57.5% is obtained using the proposed acoustic phonetic parameters on the TIMIT database.
The Voice Quality Improvement by Bone Conduction Feedback Compensation in Mobile Phone
Park, Hyung-Woo ; Lim, Won-Seok ; Bae, Myung-Jin ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 359~366
DOI : 10.7776/ASK.2012.31.6.359
Today, people are exposed to the various noisy environments, such as in the buses, subway and supermarkets where there are a lot of people. The noise issue is getting more serious as people want to use portable sound equipment and mobile phones even under this noisy condition. People want to use the portable equipment to exchange the information freely and they set the volume as 15dB higher than the noise around them, which almost reach at 110 dB. That amount of sound can cause noise induced deafness to the users and another issue to the others as additional noise source. A Bone-conduction system can be a solution to reduce noise and enhance voice signal of mobile phone. In this paper, we propose the way of cancelling noise and enhancing speech signal of mobile phones, by installing bone-conduction feedback system with ordinary mobile phones. With this system, we can reduce the environment noise and enhance the voice quality of mobile phones. Using this method, we can enhance the signal by around 17 dB.
64 Channel Noise Masking Digital Hearing Aid Firmware Development
Jarng, Soon-Suck ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 367~372
DOI : 10.7776/ASK.2012.31.6.367
This paper introduces noise masking algorithm for 64 channel digital hearing aid. 125 Hz spectral resolution is maintained for 64 channels from 125 Hz to 8000 Hz. The same spectral masking processing effects as the cochlea are considered and applied for the present hearing aid noise reduction processing algorithm. Theoretical algorithm has been ported into assembler language program software and been embedded into a DSP IC chip for the digital hearing aid. Some parts of noise masking software program code are explained, and the results of the real-time noise reduction are verified by electro-acoustic measurements.
Performance Analysis of Underwater Acoustic Communication Systems Using Underwater Channel Simulation Tool
Oh, Se-Hyun ; Kim, Hyeon-Su ; Kim, J.S. ; Cho, Jung-Hong ; Chung, Jae-Hak ; Song, H.C. ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 373~383
DOI : 10.7776/ASK.2012.31.6.373
The performance of underwater acoustic communication system is sensitive to the Doppler shift and ISI(Inter-Symbol Interference). Therefore, the simulation algorithm needs to consider time-spread due to multipath arrivals which cause the ISI, and time-varying Doppler shift along with moving source and receiver. For this purpose, VirTEX(Virtual Time series EXperiment) based on Ray model has been developed. In this paper, VirTEX is used to compare the characteristics of ocean waveguide from the experimental data and illustrate the performance. The CIR(Channel Impulse Response) that characterizes the multipath arrivals with representative time-spread due to multipath arrivals is compared between numerically simulated and experimental probe signal. Also, the communication performance analysis for BER(Bit Error Rate) is compared between numerically simulated and experimental data signal. As a result, VirTEX can be useful as a simulation tool for evaluating the performance of underwater acoustic communication system.
A DEMON Processing Robust to Interference of Tonals
Kim, Jin-Seok ; Hwang, Soo-Bok ; Lee, Chul-Mok ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 384~390
DOI : 10.7776/ASK.2012.31.6.384
Passive sonars employ DEMON(Detection of Envelope Modulation on Noise) processing to extract propeller information from the radiated noise of underwater targets. However, the conventional DEMON processing suffers from the interference of tonal signals because it extracts propeller signals and some types of tonal signals as well. If there are some tonals in the frequency band for DEMON processing, the conventional DEMON processing may additionally extract frequency informations originated from the interaction between different tonals. In this paper, we propose a modified DEMON processing, which can eliminate the interference of the tonals. The proposed algorithm removes tonals in DEMON processing band before demodulation processing, hence results the robustness to the interference of the tonals. Some numerical simulations demonstrate the improved performance of the proposed algorithm against the conventional algorithm.
Broadband Noise Prediction of the Ice-maker Centrifugal Fan in a Refrigerator Using Hybrid CAA Method and FRPM Technique
Heo, Seung ; Kim, Dae-Hwan ; Cheong, Cheol-Ung ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 391~398
DOI : 10.7776/ASK.2012.31.6.391
In this paper, prediction of centrifugal fan was conducted through combination the hybrid CAA method which was used to predict the fan noise with the FRPM technique which was used to generate the broadband noise source. Firstly, flow field surround the centrifugal fan was computed using the RANS equations and noise source region was deducted from the computed flow field. Then the FRPM technique was applied to the source region for generation of turbulence which satisfies the stochastic features. The noise source of the centrifugal fan was modeled by applying the acoustic analogy to the synthesized flow field from the computed and generated flow fields. Finally, the broadband noise of the centrifugal fan was predicted through combination the modeled noise source with the linear propagation which was realized using the boundary element method. It was confirmed that the proposed technique is efficient to predict the tonal and broadband noises of centrifugal fan through comparison with the measured data.
Measurement of the Shear Modulus of an Ultrasound Tissue Phantom
Park, Jeong-Man ; Choi, Seung-Min ; Kwon, Sung-Jae ; Jeong, Mok-Kun ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 399~409
DOI : 10.7776/ASK.2012.31.6.399
In this paper we propose a method for measuring the shear modulus of an ultrasound soft tissue phantom using an acoustic radiation force. The proposed method quantitatively determines the shear modulus based on the rise time of a displacement induced by an acoustic radiation force at the focal point of a focused ultrasound beam. The shear wave speed and shear modulus obtained from the proposed method and a shear wave propagation method were compared to verify the validity of the proposed method. In the shear wave propagation method, the shear modulus is first computed by measuring the propagating speed of a shear wave induced in a phantom by a limited-diffraction transmit field, and then was compared to that obtained with the proposed method in an ultrasound data acquisition system calibrated based on the first computed shear modulus. The relative errors between the two methods were found to be 4% for shear wave speed and less than 9% for shear modulus, confirming the usefulness of the proposed method.
Improved Synthesis Method of Negative Inter-channel Correlation Parameter Based on Anti-phase Primary Component
Hyun, Dong-Il ; Lee, Seok-Pil ; Park, Young-Cheol ; Youn, Dae-Hee ;
The Journal of the Acoustical Society of Korea, volume 31, issue 6, 2012, Pages 410~418
DOI : 10.7776/ASK.2012.31.6.410
Parametric stereo(PS) and MPEG surround(MPS) are major spatial audio coding(SAC) tools. In this paper, the problem of the inter-channel correlation(ICC) synthesis in the conventional SAC is analyzed. Conventional methods assume that ambient components mixed to two output channels are anti-phased, while the primary components are assumed to be in-phased. This assumption can cause excessive ambient mixing for a negative-valued ICC. As a remedy to this problem, we propose a new ICC synthesis method based on an assumption that the primary components are anti-phased each other for a negative ICC. The proposed method is also applied to the approximation which works in practice. The performance of the proposed method was evaluated by computer simulations and the subjective listening tests verified that the proposed method is effective in not only headphones but also loudspeakers playback.