pyglet uses OpenAL for audio playback, which includes many features for positioning sound within a 3D space. This is particularly effective with a surround-sound setup, but is also applicable to stereo systems.
A Player in pyglet has an associated position in 3D space -- that is, it is equivalent to an OpenAL "source". The properties for setting these parameters are described in more detail in the API documentation; see for example Player.position and Player.pitch.
The OpenAL "listener" object is provided by the pyglet.media.listener singleton, an instance of Listener. This provides similar properties such as Listener.position, Listener.forward_orientation and Listener.up_orientation that describe the position of the user in 3D space.
Note that only mono sounds can be positioned. Stereo sounds will play back as normal, and only their volume and pitch properties will affect the sound.