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Analysis of free field for Acoustic Anechoic Chamber based on Time Stretched Pulse  

Kim, Keon-Wook (Division of Electronics and Electrical Engineering, Dongguk University)
Publication Information
Journal of the Institute of Electronics Engineers of Korea SP / v.49, no.4, 2012 , pp. 111-119 More about this Journal
Abstract
Time Stretched Pulse (TSP) is used for transmitting and analyzing the impulse signal over the designated spatial place. However, if transfer functions of transmitter and receiver are unknown, performance investigation of free field in temporal domain is barely possible due to the overlap between the direct and indirect signal from the space. Generally, the free field or hemi-free field is evaluated by the Annex A of ISO 3745 in which utilizing the inverse square law with one-third octave band signals. In this paper, the author performs analysis of free field via applying TSP with inverse square law and the results are compared with the one-third octave band signals. According to the analysis of deviation between the corresponding signal and inverse square law model, the proposed TSP method provides the comparable performance index to the one-third octave band signal with reduced measuring time. Provided that the pre-whitening can be implementable by employing the speaker and microphone transfer function, further analyses from TSP compression are able to be performed such as multipath separation from time domain data. The anechoic chamber used in this experiment is verified conformance with ISO 3745 for free field and hemi-free field condition for limited frequency of the signal.
Keywords
Time Stretched Pulse; Free Field; ISO 3745; Anechoic Chamber; Inverse Square Law;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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1 A. J. Berkhout, D. de Vries, and M. M. Boone, "A new method to acquire impulse responses in concert halls," J. Acoust. Soc. Am., Vol. 68, pp. 179-183, 1980.   DOI   ScienceOn
2 N. Aoshima, "Computer-generated pulse signal applied for sound measurement," J. Acoust. Soc. Am., Vol. 69, pp. 1484-1488, 1981.   DOI   ScienceOn
3 Y. Suzuki, F. Asano, H. Y. Kim, and T. Sone, "An optimum computer-generated pulse signal suitable for the measurement of very long impulse responses," J. Acoust. Soc. Am., Vol. 97, pp. 1119-1123, 1995.   DOI   ScienceOn
4 D. D. Rife, and V. John, "Transfer-Function Measurement /w. Maximum-Length Sequences," J. Audio Eng. Soc., Vol 37, pp. 419-444, 1989.
5 J. Schoukens, R. Pintelon, E. van der Ouderaa, and J. Renneboog, "Survey of excitation signals for FFT based signal analyzers," IEEE Trans. Instr. and Measur., Vol. 37, pp. 342-352, 1988.   DOI   ScienceOn
6 International Organization for Standardization, "Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for anechoic and hemi-anechoic rooms," ISO 3745, 2003.
7 J. Wang, and B. Cai, "Calculation of free-field deviation in an anechoic room," J. Acoust. Soc. Am., Vol. 85, pp. 1206-1212, 1989.   DOI
8 K. A. Cunefare, and et al. "Anechoic chamber qualification: traverse method, inverse square law analysis method, and nature of test signal," J. Acoust. Soc. Am., Vol. 113, pp. 881-892, 2003.   DOI   ScienceOn
9 K. A. Cunefare, J. Badertscher, and V. Wittstock, "On the qualification of anechoic chambers; Issues related to signals and bandwidth," J. Acoust. Soc. Am., Vol. 120, pp. 820-829, 2006.   DOI   ScienceOn
10 G. Alfageme, S. Bote, and B. Martin, "New measurement methods for anechoic chamber characterization," AES 124th Conv. Amsterdam, Holand, 2008.
11 S. Schneider, "Numerical prediction of the quality of an anechoic chamber in the low frequency range," J Sound Vib., Vol. 320, pp. 990-1003, 2009.   DOI   ScienceOn
12 K. Kim, "Design and analysis of experimental anechoic chamber for localization," J. Acoust. Soc. Kor, Vol. 31, No. 4, pp. 225-234, 2012.   DOI   ScienceOn
13 Am. National Standards Institute, "Octave-Band and Fractional-Octave-Band Analog and Digital Filters," ANSI/ASA S111-2004(R2009), 2004.