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# Session 05: Browser Audio Runtime and Controls

**Session ID**: `phase04-session05-browser-audio-runtime-and-controls` **Package**: apps/web **Status**: Complete **Estimated Tasks**: \~16-24 **Estimated Duration**: 2-4 hours

***

## Objective

Implement opt-in browser audio behavior with cataloged assets, safe settings, visible equivalents, lazy-loading, and fallback states.

***

## Scope

### In Scope (MVP)

* Wire cataloged voice, SFX, alert, celebration, or music records only where Phase 04 requirements approve runtime use.
* Keep audio muted or disabled by default unless current settings explicitly opt in.
* Preserve browser autoplay compatibility through gesture-compatible start, pause, resume, and failure handling.
* Add visible captions, labels, toast feedback, or static state equivalents so audio is never required to understand product state.
* Add settings controls for audio availability, volume or mode where scoped, reduced-motion interaction, and storage recovery.
* Add unit and browser-facing tests for muted state, opt-in state, failed loads, unavailable assets, duplicate playback guards, and cleanup.

### Out of Scope

* Copying or transforming quarantined audio into runtime paths.
* Building hosted audio storage, account-synced preferences, voice generation flows, or collaboration audio.
* Adding background music to the full app unless earlier Phase 04 sessions explicitly scope and approve it.

***

## Prerequisites

* [x] Session 02 catalog records include approved audio categories and runtime paths.
* [x] Session 03 draft generation has produced or explicitly deferred any needed first-draft audio assets.
* [x] Session 04 promotion tooling can verify audio file existence, metadata, duration, format, and byte budgets where relevant.
* [x] UX requirements for captions and visible equivalents are updated.

***

## Deliverables

1. Opt-in browser audio runtime or integration.
2. Settings controls and storage recovery for audio behavior.
3. Visible equivalents for audio events.
4. Tests for playback state, fallback state, privacy, and cleanup.

***

## Success Criteria

* [x] Audio never plays before explicit user opt-in or gesture-compatible enablement.
* [x] Muted, unavailable, failed, and reduced-motion states remain understandable through visible UI.
* [x] Runtime audio uses cataloged approved assets and validates cleanup after playback or component unmount.


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