An Impedance Composite Broadband Noise Cancellation Structure

Abstract

The invention provides an impedance composite broadband noise reduction structure, comprising: an outer frame, a perforated sound-absorbing panel, a plurality of longitudinal sound-absorbing modules and a horizontal sound-absorbing module, the outer frame is formed by splicing several perforated plates, and has an opening , the perforated sound-absorbing panel is fixed in the outer frame, including the rear part facing the opening of the outer frame and the front part on the opposite side, and a plurality of longitudinal sound-absorbing modules are arranged between the outer frame and the front part of the perforated sound-absorbing panel, longitudinally The gaps between the sound-absorbing modules are arranged, one end of the longitudinal sound-absorbing module is fixed to the outer frame, and the transverse sound-absorbing module is arranged between the rear of the perforated sound-absorbing panel and the opening of the outer frame and fixed in the outer frame, the impedance The composite broadband sound-absorbing structure is at least fixedly installed on the indoor walls and ceilings. The invention realizes sound consumption and attenuation based on material sound absorption and orifice plate resonance. Compared with wedge and ordinary flat plate structures, it uses less sound-absorbing materials and takes up more space. Smaller, lower cut-off frequency.

Description

technical field [0001] The invention relates to the technical field of indoor noise reduction, in particular to an impedance composite broadband noise reduction structure. Background technique [0002] To simulate a free sound field or a semi-free sound field space indoors, it is necessary to satisfy the sound absorption coefficient of the wall to be above 99%, and the reflection coefficient of the semi-free field floor to be above 95%. The frequency range of human audible sound is from 20Hz to 20000Hz, because the lower the frequency, the longer the wavelength, the more difficult it is to absorb sound. According to the characteristics of the sound-absorbing material, the lower the frequency, the higher the thickness of the sound-absorbing material required. The cut-off frequency refers to above this frequency, the sound absorption system of the wall can guarantee the sound absorption coefficient of 99%. [0003] In order to construct the above-mentioned acoustic environme...

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Problems solved by technology

[0006] Aiming at the defects in the prior art, the present invention provides an impedance composite broadband noise-absorbing structure, which can solve the problem that the existing wedge-shaped noise-absorbing structure occupies a large space, consumes a lot of materials, and uses a flat plate structure with a high cut-off frequency (the lower the cut-off frequency The better), the low-frequency sound absorption effect is poor, etc.

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