AN ACOUSTIC DECAY MEASUREMENT BASED ON TIME-FREQUENCY ANALYSIS USING WAVELET TRANSFORM
✍ Scribed by S.-K. LEE
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 467 KB
- Volume
- 252
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
In acoustic decay measurement using the third-octave band pass "lter, it is known that an inevitable experimental error is produced by &&ringing'' at the tail part of the impulse response of the third-octave band pass "lter. This ringing gives rise to distortion of the decay curve. In order to reduce this error and to obtain an acceptable acoustic decay curve, it has been recommended that the product of the 3 dB bandwidth B of the third-octave band pass "lter and the reverberation time ¹ of the room under test be at least 16. For a listening room having short reverberation time and at the low-frequency band with narrow bandwidth, the decay curve cannot, therefore, be measured reliably by using the third-octave band pass "lter. In this paper, the continuous wavelet transform (CWT) has been proposed to determine accurately the decay curve with a low value of B¹ . The CWT decomposes an acoustic decay signal into time}frequency domain using the third-octave band wavelet "lter bank. When the CWT is applied to the measurement of an acoustic decay curve, it is found that the requirement B¹ '16 can be replaced by the replacement B¹ '4.