A probabilistic method for analysis of sound localization performance

We propose a novel probabilistic method for quantitative analysis of the sound localization performance. The analysis is based on the two kinds of probability distributions estimated from a single dataset containing listening test results for sound localization. The quantitative parameters of the von Mises probability distributions provide meaningful interpretations on the localization performance. The mean direction represents the listener’s perceptual bias, and the shape parameters and the circular variance provide information on how much the responses are concentrated about the mean direction. The front–back confusion can be determined more systematically by the proposed method than the conventional one, especially for the responses near the boundary of front–back confusion region based on the conventional criterion. The proposed method can be easily extended to analyze the up–down and left–right confusions. To investigate the feasibility of the proposed method, the already published dataset originally obtained by Iida et al. was analyzed using the proposed probabilistic method. The results showed that the proposed method can provide meaningful and reasonable interpretations on the localization performance.