Akiko Fujise

Comparison between individualization methods of spatialization for bone conducted sound in navigation task for walking subjects

Recent work in human-machine interaction and audiology has indicated the effectiveness of using spatialized bone conduction (BC) hearing in augmented reality (AR) environments. For broader applications, individualization methods are preferred, as they require simpler computation and measurement, despite the fact that spatial hearing for BC is not yet well investigated at individual levels. Accordingly, this study examines different individualization techniques for spatial audio using BC applied to a navigation task with a moving virtual sound object in external noise, which simulates a common situation in AR environments. The tested methods include one based on individually measured head-related transfer functions (HRTFs), generic HRTFs, and a modified version based on these. Subjects are instructed to follow a virtual sound source presented from the BC headphones while walking. The virtual sound source is updated so that the source is located ahead of the subject according to the subject’s location and h...

Model experiments on the ‘‘sawari’’ mechanism: Vibrational behavior of a string with a moving boundary

The ‘‘sawari’’ mechanism, seen in some plucked string instruments like Japanese biwa and shamisen, produces the vibration of the string with a moving boundary and results in its unique sustaining tone, whose elaborate tuning is essential in Japanese traditional music. Since a slight change of the sawari surface’s shape strongly affects the tone quality, it is important to examine the relationship between the boundary shape and the consequent vibration in reality. In this presentation, some results of model experiments on a string with the sawari mechanism are reported and discussed. By using a high‐speed digital video camera and a piezo‐electric pickup, the overall string motion and the local interaction between the string and the boundary surface are experimentally measured under several sawari conditions. The results are analyzed by applying image processing to video data and also time‐frequency analysis to acceleration signals, then compared between basic shapes (plain and curved), widths, and shaven d...