Rotating the AudioListener flips stereo channels

[pekeler]

Description

When a listener is rotated around its x-axis, PositionalAudio from its right side comes out of the left speaker.

A rotational angle between -pi/2 and +pi/2 is fine. Other angles flip the left/right audio.

Reproduction steps

1. AudioListener at 0, 0, 0
2. PositionalAudio at 1, 0, 0, i.e. on the right side
3. play audio and confirm sound comes from right speaker
4. rotate the AudioListener around x-axis by PI
5. notice how the sound comes from the left speaker now

Code

const listener = new THREE.AudioListener();
camera.add(listener);
listener.rotation.x = Math.PI;

const audio = new THREE.PositionalAudio(listener);
audio.setLoop(true);
audio.position.set(1, 0, 0);

Live example

jsfiddle

Screenshots

No response

Version

0.176.0

Device

Desktop

Browser

Chrome

OS

MacOS

[pekeler]

Rotating the listener around its z-axis is also producing an unexpected result: the sound keeps coming from the right speaker regardless of rotation angle.

Rotating the listener around its y-axis behaves exactly as I'd expect: the sound is moving between left and right speaker.

[WestLangley]

Nice find! 👍

[DVLP]

Shouldn't the computed "up" still be based on the local "up" ?
I mean, from:
_up.set( 0, 1, 0 ).applyQuaternion( _quaternion );
To:
_up.copy( this.up ).applyQuaternion( _quaternion );