Study On A Computational Method For Mapping Acoustic Pressure Field To Sound Quality Objective Parameter Field

Traditionally the annoyance due to noise in interior space is often predicted and evaluated with sound pressure level(SPL).However,SPL cannot sufficiently represent the accurate sensation of human‘s auditory perception subjectively and objectively,so the noise control based on sound quality metrics should be carried out for the interior space such as airplanes,cars,high-speed rail and manned submarines.Moreover,although sound quality analysis at a measured location can reveal the relationship between objective parameters of sound and human‘s auditory perception,it couldn‘t give the distribution of sound quality objective metrics in the entire interior space.Therefore,this thesis proposes a computational algorithm to map the sound pressure field to the field of sound quality objective parameters based on Spherical Nearfield Acoustic Holography(SNAH).The methodology obtains not only the spatial distribution of sound quality objective parameters,but also directly reveal the most critical sound source which mostly deteriorate people‘s perception to sound.Finally,this methodology could give a guide to interior noise reduction design in a way more effectively.The main work and results are summarized as follows:In Chapter 1,the background and significance of this study are presented in detail.The mathematical models and analysis methods of sound quality objective parameters are summarized,the limitations of current measurement techniques of sound quality objective parameters are discussed.In Chapters 2 and 3,the computational models to map the sound field to the sound quality objective parameter models are derived.The corresponding numerical simulations are studied,and digital artificial head are used for doing the validation experiments in an anechoic chamber.In Chapter 4,a method based on spherical NAH theory,which could be used to achieve 3D visualization of sound quality objective parameters,is introduced.The numerical simulations of the spatial distribution of sound quality objective parameters mapped from the sound field generated by one or two monopole sound sources are carried out.The impact of the source frequency,the angle between the sound source and the reconstruction radius on the accuracy of mapping are dicussed,respectively.In Chapter 5,the experiments are conducted to verify the computational method,where a single speaker or two speakers were taken as the sound source,respectively.Finally,the work of this paper is summarized;the limitations of the proposed computational methodology are analized and the further research focuses are proposed.