Detection of specular and diffuse reflections in concert halls using continuous wavelet transforms
Jin Yong Jeon, Muhammad Imran · The Journal of the Acoustical Society of America · 2013
Specular and diffuse reflections have been detected in fine spatio-temporal structures of room impulse responses (IRs) at different positions in a 1:10 scale model hall. Continuous wavelet transformation (CWT) coefficients were calculated using mother wavelet functions of the Daubechies wavelet families and specular reflections along with their degrees of diffuseness were investigated from the IRs. In CWT analysis, the early specular reflections were detected by fining their similarities with mother wavelet at different scales. While these reflections were treated as “defects” or “singularities” that embedded in the Schroeder decay curve. In addition, the time difference of arrival (TDOA) was applied to localize the reflections using a cross correlation function for time delay estimation and direction finding of binaural room IRs. The spectral characteristics in terms of delay time were calculated by auto-correlation and interaural cross-correlation functions (ACF/IACF).