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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
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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
Measurement of Spatial Coherence of Active Acoustic Sensor Array Signal
Park, Joung-Soo ; Kim, Hyoung-Rok ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 205~213
DOI : 10.7776/ASK.2012.31.4.205
Active acoustic array signal was measured in the East Sea and the South sea and spatial coherence was analyzed. The measurement of ambient noise, target reflection signal, sea surface backscattering signals took place including environmental measurements of sea wind, and vertical temperature profiles. The spatial coherence of ambient noise was lower than that of target reflection signal in the South Sea. The spatial coherence of target reflection signal was above 0.5 over all array length. The spatial coherence of sea surface backscattering signal was higher in high incident angle. The maximum non-dimensional array length was 3.0 (
) and 3.5 (
) to have spatial coherence above 0.5 in the East Sea. To find a design criteria for array configuration and array performance, more measurements of temporal and spatial coherence will be needed continuously in the future.
Design of Multichannel Spherical Loudspeaker Array for the Spatial Sound Manipulation
Kang, Dong-Soo ; Choi, Jung-Woo ; Lee, Jung-Min ; Kim, Yang-Hann ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 214~224
DOI : 10.7776/ASK.2012.31.4.214
The objective of this paper is to design multichannel spherical loudspeaker array by considering various positioning methods such as Gaussian grid, Lebedev grid and packing method. For the spatial sound manipulation, which is to make desired sound field by controling multiple sound sources, the Kirchhoff- Helmholtz integral states that sound fields can be reproduced in terms of infinite control sources on the integral surface. But since we cannot control infinite number of sources for the implementation, we have to allocate finite number of sound sources which can approximately act as infinite number of sources. To manipulate sound field inside of a sphere (which is typical example of three dimensional array) by controlling sound sources on the surface, three methods of allocating sound sources, which are Gaussian grid, Lebedev grid and packing method, are reviewed. For each geometry, the performances of manipulation rendered by time-reversal operator and higher-order ambisonics are compared.
Design and Analysis of Experimental Anechoic Chamber for Localization
Kim, Keon-Wook ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 225~234
DOI : 10.7776/ASK.2012.31.4.225
The anechoic chamber is essential tool to measure the various acoustic parameters with high precision. The chamber provides the climate controlled indoor environments but requires the dedicated room at a great cost in order to isolate and absorb sound field. Provided the purpose of the chamber is specific to the experiments of sound localization, the performance requirements excluding free field can be alleviated for cost effective solution. This paper designs low cost and profile anechoic chamber based on acoustic pyramids and evaluates the performance specified by the Annex of ISO 3745. Data analysis is employed to measure the free and hemi-free field performance over five straight paths for working areas and four paths for non-working areas. The identical two measurement campaigns were conducted for free and hemi-free field chamber which is easily interchangeable by simple labor in this chamber design. In the working area with conventional speaker, the results of these analyses demonstrate that lab-designed anechoic chamber is in conformance with ISO 3745 for 250 Hz - 16 kHz one-third octave band at free field chamber and for 1 kHz - 16 kHz one-third octave band at hemi-free field chamber.
Case Study of a Dog Vocalizing Human's Words
Kyon, Doo-Heon ; Bae, Myung-Jin ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 235~243
DOI : 10.7776/ASK.2012.31.4.235
This paper studies characteristics and causes of sound, and many others by distinguishing passivity and activity of the cases of a dog vocalizing human's words. As a result of the previous cases of vocalization of human's words, the dog was able to understand characteristics of a host's voice and imitate the sound using his own vocal organs. This is the case of passive vocalization accompanied by temporary voice imitation without a function of communication. On the contrary, as a consequence of the recently reported case in which a dog vocalizes such words as "Um-ma" and "Nu-na-ya," it shows the vocalization pattern clearly distinguished from the prior cases. The given dog repeatedly vocalizes pertaining words in an active manner according to circumstances and plays a role of fundamental communication and interaction with its host. The reason why the dog can vocalize the man's words actively is determined to be that the dog has a high level of intelligence and intimacy with its host, that people react actively to its pertaining pronunciation, and so forth. The following results can be used for the study that investigates animals' sound with vocalization possibility and language learning feasibility.
Correlations between Acoustic Properties and Bone Mineral Density in Bovine Femoral Trabecular Bone In Vitro
Hwang, Kyo-Seung ; Seo, Dong-Wan ; Lee, Kang-Il ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 244~252
DOI : 10.7776/ASK.2012.31.4.244
The purpose of the present study is to investigate the correlations between acoustic properties, such as speed of sound and normalized broadband ultrasound attenuation, and bone mineral density in femur with high fracture risk. The speed of sound and the normalized broadband ultrasound attenuation in 15 bovine femoral trabecular bone samples in vitro were measured by using a through-transmission method with two matched pairs of ultrasonic transducers with center frequencies of 0.5 and 1.0 MHz. The volumetric bone mineral density of the trabecular bone samples was measured by using micro-computed tomography. The bone mineral density exhibited strong correlations with both the speed of sound and the normalized broadband ultrasound attenuation measured by using the 0.5 and the 1.0 MHz transducers. The highest correlation was found between the bone mineral density and the normalized broadband ultrasound attenuation measured by using the 0.5 MHz ultrasonic transducers. The results suggest that the acoustic properties measured in the femur in vitro can be used as indices for the prediction of femoral bone mineral density.
Resources for Success in Experiment: Goldingham's Measurement of the Velocity of Sound
Ku, Ja-Hyon ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 253~259
DOI : 10.7776/ASK.2012.31.4.253
Goldingham's measurement of the velocity of sound undertaken in the early nineteenth century was the first large-scale measuring enterprise which considered various meteorological factors such as temperature, humidity, atmospheric pressure, the direction of the wind, etc. Goldingham's successful performance of measuring the velocity of sound by employing the sounds of cannons as sound source in Madras (now Chennai), a colonial region of India, for one and a half years was supported by material, institutional and social resources. As the official astronomer at the Madras Observatory, he was benefitted by the undemanding employment of accurate measuring instruments under the support of the Madras Army enabled him to gain reliable data and his reputation as professional experimentalist facilitated the acknowledgment of their trustworthiness.
A Robust Audio Fingerprinting Method Based on Segmentation Boundaries
Seo, Jin-Soo ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 260~265
DOI : 10.7776/ASK.2012.31.4.260
A robust audio fingerprinting method is presented based on segmentation boundaries. In order to obtain robustness against linear speed changes, fingerprint extraction and matching are synchronized with the segmentation boundaries. Experimental results show that the proposed method is also robust against other common audio processing steps including low bit-rate compression, equalization, and time-scale modification.
Speaker Segmentation System Using Eigenvoice-based Speaker Weight Distance Method
Choi, Mu-Yeol ; Kim, Hyung-Soon ;
The Journal of the Acoustical Society of Korea, volume 31, issue 4, 2012, Pages 266~272
DOI : 10.7776/ASK.2012.31.4.266
Speaker segmentation is a process of automatically detecting the speaker boundary points in the audio data. Speaker segmentation methods are divided into two categories depending on whether they use a prior knowledge or not: One is the model-based segmentation and the other is the metric-based segmentation. In this paper, we introduce the eigenvoice-based speaker weight distance method and compare it with the representative metric-based methods. Also, we employ and compare the Euclidean and cosine similarity functions to calculate the distance between speaker weight vectors. And we verify that the speaker weight distance method is computationally very efficient compared with the method directly using the distance between the speaker adapted models constructed by the eigenvoice technique.