Spatial Principal Component Analysis of Head-Related Transfer Functions and Its Domain Dependency

In this chapter, the Principal Component Analysis (PCA) was adopted to spatial variation of Head-Related Transfer Function (HRTF) or its corresponding inverse Fourier Transform, called Head-Related Impulse Response (HRIR), in order to compactly represent their spatial variation. This is called the Spatial PCA (SPCA). The SPCA was carried out for a database of HRTFs in all directions by selecting the domain as one of the HRIRs, the complex HRTFs, the frequency amplitudes of HRTFs, log-amplitudes of HRTFs, and complex logarithm of HRTFs. The minimum phase approximation was incorporated for the frequency amplitudes and log-amplitudes of HRTFs. Comparison of the accuracies in both time and frequency domains taking into account their influence on subjective evaluation showed that the log-amplitudes and complex logarithm of HRTFs are suitable for the SPCA of HRTFs

A Fundamental Study on Influence of Concurrently Presented Visual Stimulus Upon Loudness Perception

As a basic study on the influence of the dynamic properties of the audio-visual stimuli upon interaction between audition and vision, the effect of the simple movement involved in the visual stimulus on the loudness perception of the audio stimulus was investigated via psychophysical experiment. In this experiment, the visual stimulus given to subjects along with the audio stimulus is a bar appeared on a display, one side of which is flexibly expanding and contracting. The loudness of the audio stimulus with such a visual effect concurrently presented was rated as an absolute numerical value by using the Magnitude Estimation method. The reference of the bar length is determined so as to correspond to the Zwicker's loudness calculated for the given audio stimulus. As a result, the visual stimulus did not affect the loudness perception, when the bar was presented with its length same as the reference. On the other hand, the rating of the loudness for the same audio stimulus was significantly increased when the bar length was longer than the reference. This indicates that the change in the correspondence between the audio and the visual stimuli affect the loudness perception

Spatially Oriented Format for Acoustics (SOFA) for Exchange Data of Head-related Transfer Functions

cote interne IRCAM: Iwaya14aNone / NoneInternational audienceSpatially Oriented Format for Acoustics (SOFA) for Exchange Data of Head-related Transfer Function