THREE.Audio: Audio is already playing.

What the three.js warning "THREE.Audio: Audio is already playing." means, the isPlaying check at the top of Audio.play(), the click handlers, loops and autoplay settings that reach it, and how the paprika3d plugin's interact replies count the sounds that started before and after a pool of Audio objects.

three.js prints this warning when play() is called on an Audio or PositionalAudio whose isPlaying flag is still true. The call does nothing else: the sound that is playing keeps going, no second copy starts, and the warning is the one trace left. In a game this shows up as a sound effect that plays once and then goes quiet when the player clicks, jumps or shoots again before it has finished.

Where three.js prints it

Audio.play() in src/audio/Audio.js (three r186) returns early in two cases before it creates a source node:

play( delay = 0 ) {

	if ( this.isPlaying === true ) {

		warn( 'Audio: Audio is already playing.' );
		return;

	}

	if ( this.hasPlaybackControl === false ) {

		warn( 'Audio: this Audio has no playback control.' );
		return;

	}

Past those checks, play() creates one AudioBufferSourceNode, starts it and sets isPlaying = true. The flag goes back to false in three places: pause(), stop(), and onEnded(), which the source node calls when the buffer finishes. An Audio object therefore holds exactly one playing sound. While that sound lasts, every other play() hits the warning.

Why play() finds the sound still playing

A sound effect replayed faster than it lasts. A click, a footstep or a gunshot that calls play() on the same Audio each time is ignored until the previous one ends. A sound with a long tail or silence at the end makes this happen with slow clicking too.
play() in the animation loop. Calling it every frame, for example while a key is held, warns on every frame after the first.
Autoplay set and play() called as well. With setAutoplay(true), setBuffer() already calls play(), so a play() written after it in the loader callback warns once.
A looping sound. With setLoop(true) the source never ends, so isPlaying stays true until stop() or pause().
A suspended AudioContext. play() sets isPlaying whatever the context's state, so a sound started on load before any user gesture is counted as playing, is silent, and blocks the play() in a later click until the code calls stop() and resumes the context.

A page that reproduces it

The page draws a bell, builds a 1.5 s tone in code into an AudioBuffer, and rings one Audio on every press of the canvas:

const ring = new THREE.Audio(listener);
ring.setBuffer(buffer);
bell.add(ring);

// ring the bell on every click
renderer.domElement.addEventListener('pointerdown', () => ring.play());

paprika3d is a Claude Code plugin and MCP server that opens a three.js page in its own headless Chrome on a paused clock. The calls below were made on 2026-10-28 with the stable build, on a machine with no GPU; the run folder is written <project>, and each reply is cut to the lines discussed, verbatim.

interact {"steps": [{"mouse": "click", "x": 640, "y": 400, "frames": 10}, {"mouse": "click", "x": 640, "y": 400, "frames": 10}]}

{"after":null,"changed":{},"logs":["warn: THREE.Audio: Audio is already playing."]}
Sound: 1 started during these steps.
mouse click at (640, 400): over bell (Mesh, 3.7 units)

observe {}

{"entities":{"bell":{"type":"Mesh","position":[0,0,0]}},"harness":{"frame":21,"renderer":{"calls":1,"triangles":24,"textures":1,"geometries":1,"programs":2},"scene":{"objects":3,"meshes":1,"lights":1,"cameras":0},"errors":[],"changed":null}}

interact clicks the bell twice, 10 frames apart, well inside the tone's length. Its logs field carries the console warning from the second click, and the Sound: line counts what the page actually started: 1 sound for 2 clicks. The mouse line confirms both clicks landed on the bell, so the input is not the problem. observe has an empty errors list, since three logs this as a warning; an agent that reads errors and skips the logs would miss it. The replies say a sound started but not whether it was audible: the harness counts started sources, and on a real machine an AudioContext still suspended by the browser's autoplay rule would also start sounds that nobody hears.

The fix

When each press should restart the sound, call stop() before play(). When rings should overlap, as a bell's would, keep a few Audio objects on the same buffer and use them in turn; the buffer is shared, so the extra objects cost little:

<!-- verify -->
<!doctype html>
<html><head><meta charset="utf-8"><title>Bell</title>
<style>html,body{margin:0;overflow:hidden}canvas{display:block}</style></head>
<body>
<script type="importmap">{"imports":{"three":"./node_modules/three/build/three.module.js","three/addons/":"./node_modules/three/examples/jsm/"}}</script>
<script type="module">
import * as THREE from 'three';

const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(innerWidth, innerHeight);
document.body.appendChild(renderer.domElement);
const scene = new THREE.Scene();
scene.background = new THREE.Color(0x1d2128);
scene.add(new THREE.HemisphereLight(0xffffff, 0x334455, 2));
const camera = new THREE.PerspectiveCamera(50, innerWidth / innerHeight, 0.1, 100);
camera.position.set(0, 0, 4);

const listener = new THREE.AudioListener();
camera.add(listener);

// a 1.5 s bell tone made in code, standing in for an AudioLoader result
const ctx = listener.context, seconds = 1.5;
const buffer = ctx.createBuffer(1, Math.floor(ctx.sampleRate * seconds), ctx.sampleRate);
const data = buffer.getChannelData(0);
for (let i = 0; i < data.length; i++) { const t = i / ctx.sampleRate; data[i] = Math.sin(2 * Math.PI * 880 * t) * Math.exp(-3 * t) * 0.4; }

const bell = new THREE.Mesh(new THREE.ConeGeometry(0.7, 1, 24, 1, true), new THREE.MeshStandardMaterial({ color: 0xd4af37, side: THREE.DoubleSide }));
bell.name = 'bell';
scene.add(bell);
// one Audio plays one sound at a time: keep a few, so rings can overlap
const rings = Array.from({ length: 4 }, () => {
  const ring = new THREE.Audio(listener);
  ring.setBuffer(buffer);
  bell.add(ring);
  return ring;
});
let next = 0;

// ring the bell on every click, restarting the oldest ring when all four are sounding
renderer.domElement.addEventListener('pointerdown', () => {
  const ring = rings[next];
  next = (next + 1) % rings.length;
  if (ring.isPlaying) ring.stop();
  ring.play();
});

addEventListener('resize', () => {
  renderer.setSize(innerWidth, innerHeight);
  camera.aspect = innerWidth / innerHeight;
  camera.updateProjectionMatrix();
});
renderer.setAnimationLoop(() => renderer.render(scene, camera));
</script>
</body></html>

The same two clicks now start two sounds and log nothing:

interact {"steps": [{"mouse": "click", "x": 640, "y": 400, "frames": 10}, {"mouse": "click", "x": 640, "y": 400, "frames": 10}]}

{"after":null,"changed":{}}
Sound: 2 started during these steps.
mouse click at (640, 400): over bell (Mesh, 3.7 units)

eval {"code": "return find(\"bell\").children.map(a => a.isPlaying)"}

[true,true,false,false]

Two of the four Audio objects are sounding and two wait for the next presses. With four in the pool, a fifth press within the tone's 1.5 s restarts the oldest ring instead of being dropped. For a looping sound such as music or an engine hum, the pattern is the opposite: check isPlaying and skip play() when it is already true, or call pause() and play() to resume from where it stopped.

Where people ask about it

These threads quote the message; each count was read on 2026-10-28.

Complex PositionalAudio setup, audio gets out of sync in case of slow connection (discourse.threejs.org, 1,111 views, 10 posts)
Audio pause not working properly (GitHub, 8 comments)

Written by the paprika3d agent on 2026-10-28, reviewed weekly. Every code sample on this page ran in the harness before publishing.

Updated 2026-10-28.