Abstract: For the evaluation of human reception on noise, besides the characteristics of noise source, the binaural effect should be taken into consideration. This project aims to develop a sound quality measurement system based on binaural technology with psychoacoustics parameter. The measured results can present the human reception of noise. This project is divided into two phases and will be carried out in two years.
In the first phase, the binaural technology will be developed. The acoustic signal will be measured through the dual microphones in a binaural architecture and the human factor will be considered, i. e. , the head related transfer function will be used as the response of human auditory including psycho-acoustic parameters. It is different from the current commercial sound quality measurement system. Compared with the commercial single microphone sound quality measurement with output of loudness, the developed system is closer to human binaural hearing; and it is much simpler than the product of “artificial head acoustics”. In this project we will develop a suitable simplified model of the human ears and head with characteristics similar to real human head and ears, in which the dual microphone will be embedded. When the system is applied to measure the sound, through the post signal processing system, various psychoacoustic parameters,
such as loudness or sharpness, will be obtained. The initial study of the project has been started in begin of this year, a simplified model of the human ears and head with two micro phones system has been designed, the measurement in the anechoic room was performed, the results have been compared with results of artificial head acoustic and single microphone. The suitable simplified artificial ears and head with the computing algorithm for psycho-acoustic parameters will be developed continuously in the project. The accomplishment of the binaural technology will provide a fundamental system of measurement of sound quality for domestic demand of various industries.
In the second phase, the binaural measurement technology will be applied to identification of sound
quality for machinery noise sources. Though the performance of the developed binaural technology, not only the frequency and sound pressure level of noise source will be measured, but also its loudness, sharpness, and annoyance can be obtained further. Combined the binaural measurement technology and the computing algorithm of psycho-acoustic parameter allows simultaneous of sound source to identify the loudness or the sharpness and annoyance of the different noise sources, even if they have the same distribution of pressure level versus frequency. Under the consideration of annoying level of the machine, its structural properties should be modified in order to reduce the negative psycho-acoustic parameters, the sound quality of the noise source can be improved, e.g. mitigation of sharpness level of machine, so that the effect of the annoying noise on the emotional stability of the machine operator will be reduced.