ThreeDee : Real-time 3D Sound Processor
Introduction
ThreeDee is a 3D sound renderer running in real-time. Using openGL-based graphic user interface, you can move a single-channel sound source in 3-D space while listening to the sound from the location.
The monaural to binaural transform is modeled by a delayline and two FIR filters as shown below. They render interaural time difference (ITD) and interaural intensity difference (IID), respectively, which are known to be basic cues to localize a sound source.
We derived the delayline and filters as fuctions of a localtion from measured head-related tranfer functions (HRTFs). Instead of using the raw impulse responses, we used their minimum-phase versions not only to estimate ITD but also to efficiently model IID (i.e., reducing the number of taps in FIR filters). The details are described in the papers linked below.
Demo Examples
These two videos demonstrate sounds rendered by ThreeDee. Please listen to them WITH HEADPHONES !
Publications
- Juhan Nam, Jonathan S. Abel, Julius O. Smith, "A Method for Estimating Interaural Time Difference for Binaural Synthesis," the 125th Audio Engineering Society Convention, October 2008.
- Juhan Nam, Miriam A. Kolar, Jonathan S. Abel, "On the Minimum-phase Nature of Head-Related Transfer Functions," the 125th Audio Engineering Society Convention, October 2008.