Look at the game first. Find the engine and whether it has its own audio system, whether the game is 2D or 3D, any sounds and music already in the project, the settings menu's volume controls, and how the game pauses. Then ask the questions below.
The engine (references/engine.md): one AudioContext, unlocked on the first tap or key, a bus per category (music, effects, voice, interface) into a master with a limiter, sounds loaded and decoded ahead of use, and pausing for hidden tabs, the Harmony overlay and phone interruptions.
Sound effects (references/sound-design.md): a cue for each game event, with variation, voice limits and cooldowns, then interface sounds. A 2D game pans by screen position; a 3D game uses positional sound.
Music (references/music.md): gapless loops, crossfades between tracks, and layers or stingers if the game wants music that reacts to play.
The mix ("Mix levels" in references/sound-design.md): levels between categories, and ducking (references/music.md).
Test with the "Testing" list in references/sound-design.md. Phone speakers, headphones and an iPhone need the developer; say which checks you couldn't run.
Report to the developer: the cues added and the event each plays on, the music plan, where the volume levels live, every new file with its source and license in audio/CREDITS.md, and any choices made for them.

Ask the developer first

Ask in one round, with a recommendation for each. Don't ask what the code already shows.

Where do sounds come from? Their own files, a licensed library, or free sounds (each with its license recorded). Recommended: their own files first, then CC0 sounds. Never ship a sound without knowing its license.
What should music do? One track per screen, crossfades between areas, or layers that build with the action. Recommended: one loop per screen with crossfades; layers only when the music has stems of the same length.
Sound with the iPhone on silent? iPhones mute Web Audio when the ringer switch is on silent, unless the game opts out ("Phones" in references/engine.md). Recommended: leave it muted, since players who switch to silent expect silence.
Generators: "Do you have any of these set up? (default: none)" Sound effect and voice generation (for example ElevenLabs, or a local text-to-speech model) and music generation (for example Suno, Udio, Stable Audio, or a local model such as MusicGen). Ask; never scan for tools. With any, follow references/generators.md; without, the default path is complete.

If the developer says "you decide", use the recommendations and list them in the report as choices they can change.

Rules

One AudioContext for the whole game. Resume it in the first pointerup, touchend or keydown handler; browsers start it suspended until the player acts.
Everything through a bus. Music, effects, voice and interface each have a gain node into a master, so the settings menu's volume sliders and ducking work on whole categories.
A limiter on the master so many sounds at once never clip.
Load before use. Decode effects at load; a sound decoded on first play arrives late. Stream long music instead of decoding it whole.
Limit voices. Cap how many copies of one sound play at once, and how soon it can repeat. Fifty overlapping coin sounds are noise.
Vary repeats. Small random pitch and volume changes, or two to four variants, so repeated sounds don't grate.
Pause with the game. The pause menu, and in a game that uses the Harmony SDK the Harmony overlay (harmony.on("open") and harmony.on("close")): pause effects, and pause or duck the music. Without the SDK, the game pauses on the window's blur event, which fires when the overlay opens. In online play the game doesn't pause, but its sound can still be ducked. A hidden tab mutes the game when the player's "mute in background" setting is on, which is the default.
Every important sound has a visual cue too, for players with the sound off or who can't hear it.
Credit and license. Keep a credits file listing every sound and track with its source and license, and show attributions where licenses ask for them.

Reference files

File	Read when
references/engine.md	The AudioContext, unlocking, buses and the limiter, loading and decoding, formats, playing with voice limits, pausing and resuming, phones
references/music.md	Gapless loops, crossfades, layered music, stingers on the beat, ducking
references/generators.md	Only when the developer has a sound, voice or music generator: ground rules (no paid calls without a yes, no API keys, commercial terms, recording sources) and tips
references/sound-design.md	Cues for game events, variation, interface sounds, 2D panning and 3D positional sound, mix levels, sourcing and licenses, testing

harmony-audio

Sound and music for web games

Build order