Device and method for measuring sound reduction index of acoustic material by adopting pulse method

Abstract

The invention provides a device and method for measuring a sound reduction index of an acoustic material by adopting a pulse method. The device comprises a sound tube, a pulse sound source, microphones, a power amplifier, a signal conditioner, an adapter and a data collecting device, wherein the sound tube is formed by sequentially, coaxially and fixedly connecting one section of big-diameter cylinder tube, a conical tube and a small-diameter cylinder tube, three through holes which are vertical to the center axial line of the small-diameter cylinder tube and are used for arranging the microphones are formed in the side wall of the small-diameter cylinder tube, the pulse sound source is arranged in the big-diameter cylinder tube, and a rear cover is connected with the external end of the small-diameter cylinder tube in a threaded manner. The method comprises the steps of: firstly obtaining a frequency response function of the whole measuring system, then obtaining a drive signal frequency spectrum of the required pulse sound source, and finally measuring and driving the pulse sound source by the drive signals of the required pulse sound source to obtain the sound reduction index of a sample to be measured. Compared with a double-loading method and a double-sound source method, the device and method provided by the invention overcome the influence of acoustic impedance of the tail end of the sound tube to a test result.

Description

technical field [0001] The invention relates to the technical field of acoustic material testing, in particular to a device and a measuring method for measuring the sound insulation of acoustic materials using a pulse method. Background technique [0002] In the field of sound tube acoustic testing, the current measurement techniques for sound insulation of acoustic materials mainly include standing wave field decomposition method and transfer matrix method. Among them, the standing wave field decomposition method relies on the decomposition of the sound field inside the sound tube, and there are two main problems it faces: (1) the phase matching problem between multiple microphones, this problem can use one of the microphones as a standard, and Other microphones and their calibration methods are used to solve this problem. If a single microphone is used for point-by-point measurement, this problem does not exist, but the measurement time is longer; (2) The impact of the aco...

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Problems solved by technology

The double sound source method requires the loudspeaker to be installed twice, respectively, at the two ports of the sound tube, and the transfer matrix and sound insulation of the material can be obtained through two measurements. Obviously, this method is cumbersome in the actual operation process, although it is also It can accurately measure the sound insulation of materials, but in practical applications, it has not been popularized

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