Development of Double Nearfield Acoustic Holography Method

There are several types of sound localization methods. In middle frequency around 1kHz, These methods are effective to detect the sound source location. However, for low frequency sound under 100Hz, almost sound localization methods do not have enough resolution to detect the sound source location. To overcome this problem, the author is now developing a new sound localization method, "Double Near-field Acoustic Holography method." This method is converted method of conventional Near-field Acoustic Holography method. The Near-field Acoustic Holography method has best resolution in all sound localization method. However, for low frequency sound sources lower than 100Hz, this method dose not have enough resolution to detect the its position. The proposing Double Near-field Acoustic holography method is developed to improve the resolution of low frequency sound localization. In this paper, the experimental results with small speaker are reported. By these experiments, it is probed that the proposing Double Near-field Acoustic holography method has enough resolution to detect the position of the low frequency sound source.