Outdoor measuring method for sound barrier transition area diffraction attenuation based on directional sound source

Abstract

The invention provides an outdoor measuring method for the sound barrier transition area diffraction attenuation based on a directional sound source. The measuring method is applicable to the outdoor scene measurement, and is simple, convenient and precise; the directional sound source is adopted as a testing sound source, so as to radically prevent the influence of ground reflection and sound barrier two-end diffraction; a testing voice-frequency signal is selected reasonably and a microphone receive signal is subjected to FIR filtering, so as to reduce the influence of background noise to the greatest extent; the atmospheric attenuation modification is performed to effectively eliminate the influence of meteorologic condition variation; a common sponge is adopted as an acoustic filter, so as to attenuate an ultrasonic signal to the greatest extent and retain the voice-frequency signal at the same time; meanwhile, the measurement can be centralized and carried out in smaller areas, the sizes of measuring devices are small, the requirements for software and hardware conditions are not high, and the operation is simple and easy.

Description

technical field [0001] The invention relates to noise measurement methods in the field of environmental protection, more specifically, to an outdoor measurement method for diffraction attenuation in a sound barrier transition area based on a directional sound source. Background technique [0002] Simple and accurate measurement of the diffraction attenuation value in the transition area between the sound bright area and the sound shadow area of ​​the sound barrier has important theoretical significance for the study of the diffraction sound field of sound barriers with different top styles and the calculation of the insertion loss of the sound barrier. Acceptance provides an important basis. The area between the diffraction attenuation of 0 and the Fresnel coefficient of 0 is the sound barrier diffraction attenuation transition area, referred to as the transition area. The area between the Fresnel coefficient of 0 and the top level of the sound barrier is called the upper t...

AI Technical Summary

Problems solved by technology

However, the 5ms acoustic signal contains about 2.5 sine waves, which is easily disturbed by other external conditions, and the stability of the measurement results of this method is difficult to guarantee

And this method can only measure the diffraction attenuation noise in the upper transition region, and does not discuss the diffraction attenuation noise in the lower transition region

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