Analysis of Nonlinear Distortion in Impulse Response Measurement of Spherical Microphone Array

作者：Liu, Yu; Xie, Bo-Sun^*; Mai, Hai-Ming; Chen, Jia-Yan

来源：Journal of South China University of Technology(Natural Science Edition), 2015, 43(4): 126-132 and 137.

DOI：10.3969/j.issn.1000-565X.2015.04.018

• Excitation sources
• Impulse response measurements
• Incident sound waves
• Logarithmic sine sweep
• Maximum length sequences
• Measurement methods
• Spherical microphone array
• Spherical surface

During the impulse response measurement of spherical microphone arrays, the scattering of the incident sound wave caused by the array geometry may change the harmonic proportion of signals recorded by the microphone. In this paper, two methods, one using the maximum length sequence and the other using the logarithmic sine sweep as the excitation source, were adopted to measure the impulse response, and the effect of nonlinear distortion on the measured results was analyzed. Moreover, a simulation was carried out for comparison. Simulated and measured results indicate that (1) the proportion of harmonic distortion varies with the incident angle of sound source due to the scattering of incident sound wave on the spherical surface;(2) the microphone with a harmonic distortion array back onto the sound source slightly affects the output, while the microphone with a harmonic distortion array facing to the sound source greatly affects the output;and (3) in general, the measurement method based on the maximum length sequence is more sensitive to the nonlinear distortion of sound sources while the method based on the logarithmic sine sweep is more suitable for the impulse response measurement of spherical microphone arrays.

• 出版日期2015-4-1
• 单位华南理工大学