8 Virtual Auditory Display System



 What is gVirtual Auditory Display SystemhH

    A perceived position of sound image can be controlled by convolving HRTFs (Head-Related Transfer Functions) to the sound source at arbitrary position. We call this system gVirtual Auditory Display (VAD).h We research that establishing a high accuracy VAD system and its application to welfare.



 A high accuracy VAD system

    To accomplish a high accuracy VAD system, we research following techniques.

    • Choose the best fitted set of HRTFs
    • Presentation of sound responsive to head movement
    • Sound effect of reflection and reverberation

    In VAD responsive to head movement, HRTFs are controlled by detecting the head movement with a position sensor. Therefore, the sound image doesn't move even if the listener moves. Expressing an accurate three-dimensional sound image is possible by using individualized HRTFs.



 Application for Visually Impaired People

    For the visually impaired people, information provided by sound is particularly important in recognizing their surroundings. We aim to construct a system which can train spatial perception of three-dimensional sound space for visually impaired people using high-accurate VAD technology. The training system has been developed as game contents for improvement of QoL (Quality of life) of visually impaired people.

     Features of Our System

    • High-precision sound field : High-reality of 3D sound space is realized by our technologies.
    • Low cost performance : Digital signal processing for creation of 3D sound space is realized as middleware. Special hardware is not required, such as a DSP board.
    • A high-accuracy position sensor is originally developed.
    • Enjoyable Applications : Characteristic applications like game are developed.
     BBBeat (sound whack-a-mole game)

    • BBBeat is a training content like a whack-a-mole game, a player beat a sound bee with a hammer.
    • In this system, a VAD responsive to head movement is used, which means that the absolute position of the sound doesnft change even when the listener moves.

      BBBeat Overview of BBBeat
      FigDScreenshot for sighted peopleiLEFTjand Overview of BBBeatiRIGHTj
     Mental Mapper (cognitive-map formation)

    • Visually impaired people are not good at forming a cognitive-map (a mental map) in their mind.
    • A sound map in training can be freely edited with sound-marks.
    • Reflections and the reverberation can be added as a sound effect.

      Training Overview Map editor
      FigDTraining OverviewiLEFTjand Map editoriRIGHTj

Last update: 2017.04.28