Virtual sound localization for enhanced 3D sound: from a research project to a patent
In the FWF project "LocaPhoto," VRVis and the Academy of Sciences (ÖAW) developed an innovative sound localization model that can realistically simulate three-dimensional sound over headphones by using 3D head scans. Now the method is available as a patent for research and industry.
The localization of sound sources is one of the essential tasks of the human auditory system. At the same time, the process of how sound hits the eardrum is highly complex since the sound is also filtered through the head, ears and torso of the listener. It is crucial to understand how the sound hits the ear for the development of audio devices that can realistically simulate virtual acoustics. To do this, it is necessary to "measure" the sound and its filtering through the human anatomy. "The difficulty here," explains Andreas Reichinger, head of the LocaPhoto project at VRVis, "is that directional hearing depends individually on the direction-specific filter properties of the ear, the so-called HRTF (head related transfer function), and must therefore be individually measured for each person. However, an acoustic measurement, as performed by ARI so far, requires a lot of effort: You need a soundproof room with many loudspeakers around an automatically turned chair, tiny microphones in your ears and about 15-30 minutes of motionless perseverance while unpleasant sweep sounds are played around you."
To improve the comfort and efficiency of these sound measurements, the Acoustics Research Institute of the Austrian Academy of Sciences and VRVis have joined forces within the framework of an FWF funded research project. The method developed and meanwhile patented combines numerical HRTF calculations with 3D images to create personalized sound simulations that go far beyond ordinary stereo sound. Special rooms and long measurement sessions are thus a thing of the past since now the sound-localization model is calculated virtually - based on a 3D head scan taken from photographs.
"Sound simulations like ours, which are not only relatively convenient, quick and easy to produce with little technical effort, but above all can incorporate all directions of hearing as realistically as possible, are relevant to many areas, from hearing acoustics to medicine and research. VR and AR simulations are also an important area of application: for example, individualized directional hearing helps to steer the gaze in a certain direction or allows us to understand our acoustic environment, even when we are not looking," says Andreas Reichinger.