Application of Virtual Microphone for Noise Control in A Car Cabin

• Main Authors: Yi-Chun Chiu, 邱奕淳
• Other Authors: Shin-Hwa Liu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/zbd7mc

碩士 === 國立臺北科技大學 === 車輛工程系所 === 102 === The purpose of this study is to estimate the sound pressure perceived of driver by applying virtual microphone technique to the noise simulation of a driving vehicle. If the sound pressure is estimated correctly, it may be useful for local active noise control at a pinna. Experimental procedures are as following, first step is to choose different algorithms. Second step is recording both original and low-pass filtered noise played by the speaker in the back seat with different sampling frequency, errors will be convergence by adjusting filter length order. Third step is the same as the second step except the noise is played by the four car speakers. Fourth step, study the influence of the filter length order and microphone position on head movement of the driver. Fifth step is to investigate the choice of the different distant in the cabin positions of physical microphone by a patent. Experimental results show the error between the virtual microphone and the detective microphone at a pinna is not necessary to reduce by increasing the filter length order. Also the error will increase when the distance between physical and virtual microphone become larger by the detective microphone check. Although short distant error is reduce. However if sound is complex after physical microphone record and input to algorithm, output virtual microphone the error is increase by the detective microphone.