Multiple microphones are often used to record a single source in live and studio productions. Because such microphones are often at different distances from the source, the sum of their signals creates a comb filter response with flanging effect. These effects can be avoided if there is automated delay compensation. This article analyzes the accuracy of the Generalized Cross Correlation with Phase Transform (GCC-PHAT) as a delay-estimation technique when applied to arbitrary music signals. The authors show that the window function used in the GCC-PHAT calculation influences the interferences between frequency components with different amplitudes, which results in spectral leakage and errors in the GCC-PHAT calculation. This interference is greatest when the input signal is narrowband and when the window function has high-amplitude side lobes.
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