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Description
The characterization of sound absorption typically relies on standardized methods such as impedance tube measurements or reverberation room testing, with associated sample size, mounting conditions, or test environment limitations. This paper investigates an alternative approach based on time and space resolved acoustic imaging of reflected sound fields.The proposed method uses a rotating linear microphone array implementing coherence scanning acoustic holography to measure the sound field generated by a pulsed acoustic source placed near the array. A material sample is positioned in front of the array, allowing capture of the sound reflected by the sample. By applying temporal windowing to isolate the reflected component and spatial filtering to focus on the reflection region, the reflected sound field is reconstructed and analyzed in the frequency domain.The spectrum of the reflected signal is compared to a reference spectrum obtained with a highly reflective surface under identical conditions. The spectral difference is used to estimate the frequency dependent absorption coefficient of the sample.The objective of this study is to evaluate the feasibility, and limitations of this approach for absorption estimation, particularly for mid- to high-frequency ranges. Preliminary considerations suggest that it may offer a flexible alternative for in-situ material absorption characterization.