We now have 3D TV's that don't require 3D glasses. Is it possible to make TV's with 3D sound that only comes from it's own speakers (that is, it doesn't require external speakers) so that different sounds will seem to come from different locations in the 3D volume?

I do not think three dimensional works.

Sound perceived from above and below cannot be achieved by synthesizing a psychoacustical illusion from only two speakers. Virtual surround illusion can be created by processing audio from only two channels, but that is not 3D, it is 2D

Several companies have their own processing methods to the virtual surround.

3d sound is easiest with headphones. There are plenty of 3d sound clips for use with headphones to be found on YouTube and elsewhere on the web, most commonly demonstrations are versions of the virtual barbershop. Look them up if you have not experienced them before they are quite effective all you need is headphones and the device you used to access this forum.

 

I have watched a video on YouTube that demonstrated a way to do this with PC/laptop speakers without headphones using a clever use of interference patterns to block sounds to the opposite ear, the disadvantage is that is require the listener and speakers to be quite fixed in an ideal arrangement. And I think I have remembered enough keywords to find it again.

I don't have enough time to watch it again right now so hopefully that's the right link.