Semi-Active Sound Absorption Method with Acoustic Impedance Matching

Abstract

The active sound absorption technique excels in mitigating low-frequency sound waves, yet it falls short when dealing with medium and high-frequency sound waves. To enhance the sound-absorbing effect of medium and high-frequency sound waves, a novel semi-active sound absorption method has been introduced. This method modulates the surface impedance of a loudspeaker positioned behind the sound-absorbing material, thereby altering the sound absorption coefficient. The theoretical sound absorption coefficient is calculated using MATLAB and compared with the experimental one. Results show that the method can effectively modulates the absorption coefficient in response to varying incident sound wave frequencies,ensuring that it remains at its peak value.

Keywords

acoustic impedance / semi-active sound absorption / rigid wall / cavity depth / sound absorption coefficient

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Funding

National Natural Science Foundation of China(51705545)