Transformation of sound by a phononic crystal
نویسندگان
چکیده
Several noise barriers made of phononic crystals (i.e. manmade composite materials with a periodic structure) have been designed over the last decade. The periodic structure of phononic crystal avoids sound propagation in a defined frequency range called Bragg band gap (i.e. waves are evanescent). This study aims at quantifying the perceptual impact of a noise barrier based on a phononic crystal in terms of noise annoyance attenuation. First, a specific phononic crystal has been designed to study timbre modifications. Then, a combined acoustics/auditory analysis of noise barrier made of a phononic crystal is employed. The acoustic analysis consists in numerical simulations and measurements of acoustical scenes. In addition, several psychoacoustics parameters are estimated from the synthesized/recorded acoustic signals. In details, two specific timbre features are studied: the spectrum and temporal modifications of the sound source.
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