Blind Estimation Of Reverberation Time Based On Maximum Likelihood Estimation

During propagation,Acoustic waves reflected by wells?celling and floor form faded tail called reverberation.Reverberation reach ear or microphone with direct sound signal and effect original intelligibility of speech and communicate systems.This reverberation will bring inconvenience to people's language communication,voice communication system and so on.With the development of science and technology,dereverberation technology has been applied to more and more fields,such as building acoustics,sound source localization,speech recognition and so on.Reverberation time is an important parameter in dereverberation process.At the same time,the reverberation time also plays an important role in the objective evaluation of the acoustical quality of the auditorium and the measurement of the sound absorption of materials.There are many methods of reverberation time measurement,which are divided into blind estimation and non-blind estimation.The maximum likelihood estimation algorithm is the most used in blind estimation,i.e.,using the reverberant speech signal naturally uttered by the speaker to estimate reverberation time.An improved algorithm for blind estimation of reverberation time based on maximum likelihood is presented in this paper,Firstly,special rules for defining the optimal boundaries of the speech decay segments are introduced.Then,two additional parameters are calculated to select the speech decay segments for maximum likelihood estimation.Finally,the reverberation time is estimated based on the maximum likelihood estimation using the selected speech decay segments.The simulation experiment is carried out through MATLAB,and the experimental results show deviation and their variance between the estimated reverberation time and the true value are decreased.In order to apply the algorithm to the actual measurement,this paper uses MATLAB GUI to design a reverberation time estimation system.The system mainly plays a white noise signal through the loudspeaker,then receives the recorded voice signal through the microphone,and calculates the impulse response of the room through Wiener filtering.Finally,the corresponding reverberation time is calculated by using the Schroeder integrated impulse response algorithm and the maximum likelihood reverberation time blind estimation algorithm.The results are displayed on the interface,basically the same.Therefore,this system realizes the function of real-time measurement of the reverberation time of the room.