To isolate the scattering from the sample under test (rectangle in B), a background measurement containing the direct sound and the room interference is subtracted. The speaker / microphone response is then deconvolved from the measurement and the scattered data are windowed. These windowed data for all of the angles of observation are concatenated in Figure 2C in the form of a "temporal" angular response. Each impulse response is transformed into its frequency response, Figure 2D, and 1/3 octave polar responses are obtained, Figure 2E. The auto correlation of these polar responses is used as a diffusion coefficient metric and is plotted versus frequency to obtain the diffusion response, Figure 2F.
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Diffusion: Figure 2
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