Hi
For your AM->audio_3d_set_listener_attributes try this:
LMatrix4f mat = camera.get_mat();
LVecBase3f lv = mat.get_row3(1);
LVecBase3f uv = mat.get_row3(2);
LVecBase3f pos = mat.get_row3(3);
AM->audio_3d_set_listener_attributes(pos.get_x(),pos.get_y(),pos.get_z(), 0,0,0,
lv.get_x(),lv.get_y(),lv.get_z(),
uv.get_x(),uv.get_y(),uv.get_z());