Probably you’ve been to movies and know well what surround sound is. For this usually a bunch of speakers is positioned around you to make you feel as you are in place the movie shows. But there are techniques where same effect can be simulated with two speakers – ideally with headphones. This is so called real time head related transfer function (HRTF).
Probably you’ve seen many computer programs that do that by simply dragging imaginary sound sources around screen, so this FPGA project does this and even more including multiple sound streams that are positioned with filter coefficients stored in 512kB SRAM chip on the DE2 FPGA board; graphical user interface where sound sources can be dragged with mouse pointer.