Basic study on three-dimensional sound field auralization using a scale model

In order to achieve ambisonic three-dimensional sound field auralization using a scale model, the ambisonic recording procedure was reformulated based on a partly modified microphone arrangement. Specifically, a technique of measuring room acoustic response by changing a small microphone to various places in a scale model was introduced. In converting room acoustic responses to ambisonic signals, taking signal differences reduces the dynamic range of the low frequency range and deteriorates the sound quality of auralization. This is avoided by determining the microphone arrangement interval and measurement frequency range with the characteristics of the model sound source and the microphone SN ratio taken into consideration. The room acoustic responses measured in the divided frequency range was synthesized to obtain all the frequency range. To confirm the effectiveness of this method, ambisonic signals up to the secondary ones were prepared, and a fundamental psychological experiment on localization in the horizontal plane was conducted, and localization reproducibility equivalent to a full-scale model was confirmed. The presented sound contains no auditorily harmful noise and is expected to be applicable to subjective evaluation of the sound field of a hall.