Application Of Acoustic Simulation Technique In Assessment Of Speech Intelligibility In Auditoriums

The speech transmission quality can be assessed preferably by the "speech intelligibility", the introduction of which has significant implications for the acoustic assessment of auditoriums like theatres, conference rooms and classrooms. The conventional methods to measure speech intelligibility of an auditorium involves the measurement of objective indices or subjective evaluation by a group of listeners, both need to be done inside the auditorium. This is limited to uncontrollable factors such as time and place, and can only be realized after the completion of the building. The means of acoustic simulation technique has broad application prospects with the ability of overcoming the limitations and can even predict the speech intelligibility before the auditorium is built.The subjective and objective assessment of speech intelligibility is greatly influenced by many factors including the algorithm of the software, the equivalence of the acoustics model, the parameter settings and others, therefore it is of big complication and difficulty, In this thesis, the strategy and method of assessment of speech intelligibility in auditoriums using acoustics simulation method is systematically investigated, based on which the relationship curve between the subjective and objective results is obtained. The main works included in the thesis are as follows:(1) The fundamentals of acoustic computer simulation and speech intelligibility are briefly explained.(2) The factors affecting the results of the computer simulation are discussed. To get the strict equivalence of the model, the simulation is divided into several processes:space equivalence, sound source equivalence, listening equivalence, and relevant parameter settings. These aspects are discussed in detail. Based on the equivalence of the model, the simulation of STI and the process of subjective assessment is studied.(3) The simulation method is adopted in the assessment of four real rooms, and the relationship between the subjective and objective results are obtained.(4) The simulated results are compared with the results obtained from in-situ measurements, and the weakness and limit of acoustics simulation technique is discussed.This study has good value in guiding the proper application of acoustic simulation technique in project practice and scientific research.