Detection And Analysis Of Indoor Reverberation Time Based On M-sequence

Reverberation time is the most important parameter in architectural acoustics.Reverberation time can affect the language clarity and the sound quality of the hall.It can also be used to guide the acoustic design of acoustic buildings such as theaters and cinemas.In China,the best reverberation time in different buildings is stipulated in many architectural design codes as an index of architectural design.Accurate measurement of reverberation time is of great significance to acoustic design.In order to measure indoor reverberation time in high noise environment,this paper proposes a method based on M-sequence.This paper first summarizes the development of reverberation time measurement technology at home and abroad,studies the mainstream reverberation time measurement technology and analyzes its shortcomings and advantages.Then through the study of m-sequence,the advantages and feasibility of using m-sequence to replace the traditional digital sound source are analyzed theoretically.Then the method of using FMT to calculate the impulse response of the system is introduced,and the anti noise ability of the method is verified by simulation.After analyzing several methods of obtaining the attenuation curve of sound pressure level,the method of smoothing the attenuation curve of sound energy by sliding window is improved.Finally,the improved algorithm is applied to the design of indoor reverberation time detection system,and the measurement software based on Windows system and Android system is developed successfully,and the software is used in the actual test environment for measurement.In the actual measurement environment,after using the awa6223 + sound calibrator to calibrate the sound level meter,the indoor reverberation time measurement method based on m-sequence,the steady-state noise cut-off method and the traditional source pulse response method are respectively used to measure the reverberation time of the same classroom.Finally,comparing the measurement results,it is found that m-sequence method has a strong anti noise ability,which also shows that m-sequence can replace the traditional one The sound source is used to measure the reverberation time of the closed chamber.