The Development of Double Nearfield Acoustic Holography method

(Low Frequency Noise Source Localization of a Commercial Product)

Abstract

I am now developing a new sound localization method, Double Near-field Acoustic Holography (DNAH) method. This method is aimed to improve the resolution of low frequency sound localization. This DNAH method is converted method of conventional Near-field Acoustic Holography (NAH) method. The NAH method is said as it has best resolution in the current sound localization methods. However, the resolution of low frequency sound localization is not enough to localize the position of sound sources. In the former paper, the improved resolution of DNAH method in low frequency sound localization is proved by numerical simulations and basic experiments with speakers. By the basic experiments, the reconstructed images by DNAH method show better resolution than the images by NAH method.

In this presentation, the measurement for an actual commercial product, a window type air conditioner, was carried out. In this experiments, the images by proposing DNAH method shows the sharper image than the images by conventional NAH method. As a result, it is proved that the proposing DNAH method is effective for low frequency sound localization for the real mechanical products.