Research On Sound Transmission Loss Measuring System Of Acoustic Material

With the development of economy and technology,the sources of noise become diversified and the harm has become more and more serious in twenty-first Century.So the noise control has become imperative.In this paper,it mainly studies the evaluation and measurement methods of underwater acoustic material sound insulation performance in the perspective of transmission to reduce noise.First of all,the fundamental concepts about acoustic and the acoustical parameters of absorption coefficient and transmission coefficient are introduced.It lays the theoretical foundation for follow-up acoustic calculations.The measurement principle,experiment procedure and calculation process of sound insulation measurement systems,such as reverberation chamber method,impedance tube method and free field method,are introduced.It prepares for building appropriate sound insulation measurement system of acoustical material.Secondly,the design procedure of half bridge class D amplifier based on MOSFET is introduced in detail,including the selection of MOSFET and the design of drive circuit and protection circuit.The corresponding power module is briefly introduced according to the need of power amplifier module.The result shows that the split modular design is simple and easy to debug and maintain.Then,the working principle and acoustic performance of underwater acoustic transducer are introduced.The design scheme of tuning matching and the design procedure of matching transformer under different conditions are investigated.At last,the sound insulation measurement method of underwater acoustical material based on echo sounder is introduced in detail.It is the first time to carry out the sound insulation measurement of the material in the water with two identical transducers.The method has high test efficiency and good reception signal.Compared with the traditional testing,the measurement is low cost and easy to operate.