Acoustic imaging technology is a method of reconstructing the sound source image using the measured sound field information. If the acoustic imaging map is fused with the real object image, a graph of the noise state of the measured object is formed that can be visually analyzed. The color and brightness on the image represent the strength of the regional noise. Therefore, the acoustic imaging is a preliminary judgment of the noise source. A convenient way.
The sound field information measurement in acoustic imaging technology mainly includes two methods: sound intensity measurement and microphone array measurement.
The sound intensity measurement method is to first measure the sound intensity level of each point on a closed surface, and then obtain the sound power from the sound intensity level. Since the sound intensity is a vector, the measured value is mainly affected by the sound source perpendicular to the plane of the test probe. Therefore, it can effectively eliminate the interference of background noise and surrounding sound sources in the near-field measurement, and can ensure high sound test quality. The microphone array is a system composed of a set of microphones placed in a certain geometric structure. It can receive signals from different spatial directions at the same time. By comparing the phase difference of the noise signal to each microphone, the position of the sound source is determined according to the phased array principle. . The microphone array has the functions of filtering and denoising, sound source localization, etc., which greatly improves the quality of sound signal processing and the accuracy of sound source localization. At the same time, the multi-channel recording mode of the sound array provides for further processing of noise signals (such as noise signal separation) Condition.