Development of adaptive algorithm for active sound quality control

This paper develops an active sound-quality control (ASQC) system based on the active noise equalization (ANE) technique, and optimizes it with the filtered-error least mean square (FELMS) algorithm and normalized reference signal generator. The ASQC system controls the sound quality of products such as engines by changing the amplitudes of harmonics. This optimized system uses the FELMS algorithm to limit disturbances in the passband caused by uncorrelated interferences with high gains in the secondary path, thereby increasing the system stability. It achieves fast convergence by normalizing the amplitudes of internally generated sinusoids in the reference signal according to the magnitude response of the secondary path at the corresponding frequencies. Computer simulations demonstrate the desired spectral shaping capability with faster convergence and reduced passband disturbance.