Looks like you’ve got your settings for the listener wrong. Here is the equivalent Python code which should be pretty straightforward to convert to C++.
forward = render.getRelativeVector(camera, Vec3.forward())
up = render.getRelativeVector(camera, Vec3.up())
vel = (0, 0, 0)
audiomanager.audio3dSetListenerAttributes(pos[0], pos[1], pos[2], vel[0], vel[1], vel[2], forward[0], forward[1], forward[2], up[0], up[1], up[2])The important difference is that this command is expecting vectors, not rotations.