Pulses correspondence of reflection and incidence over periodic diffuse surfaces: further investigations

A simple approach for the assessment of the sound reflection from diffuse surfaces has been recently proposed. It is based on the similarity (i.e. the correpondence) between reflected and incident superposed sound pressure pulse signals. Due to shortcomes in assessing the sound reflection from diffuse surfaces, a n-order reflection corresponding factor (CFn) has been presented. The proposed metric is determined by the ratio between the spectrum of the product of synchronized and weighted n- order reflected and incident pulses (frequency convolution) and of the square of the incident pulse (frequency autoconvolution), indicating the spectral similarity between reflected and incident sound pressure pulses. Here further investigations on CFn are performed using a squared periodic corrugated diffuse profile. First, CFn is determined from measured impulse responses under normal incidence by varying geometric parameters of the profile, like the corrugation period, width and depth. Then the extension of the profile is modified, in order to investigate how the specular reflection is related to the quantity of corrugation periods. Finally, aiming to express CFn by a mean value, this is performed from averages of reflection pulse signals measured for normal incidence on different regions over an entire period, like a corrugation top,edge and recess.