🔊 Audio Alert Selector - Chrome Extension

📌 Overview

Audio Alert Selector is a Chrome extension that allows users to choose a specific audio output device for notifications. Unlike most applications that respect the system default audio device, this extension enforces sound routing based on a selected device, ensuring alerts are always played consistently.

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❗ Problem Statement: Why setSinkId is Needed

❌ Shortcomings of System Default Audio Routing

Typically, audio in web apps and browser-based applications plays through the system's default audio output device. However, this causes issues in multi-device setups:

1. Changing Default Devices Disrupts Alerts:
   • If the user's default sound device changes (e.g., Bluetooth headphones disconnect), alerts may route unpredictably.
2. Limited Control for Users with Multiple Audio Outputs:
   • Many users (e.g., customer service reps with speakers + headsets) need alerts on a dedicated device while continuing calls on another.
3. Web Applications Cannot Select an Audio Device Dynamically:
   • Browsers do not allow web-based applications to programmatically choose an output device unless explicitly set using setSinkId.

✅ The Power of setSinkId

• Overrides system default and forces audio to play on a specific device.
• Ensures alerts never "vanish" to unintended headphones, Bluetooth devices, or inactive speakers.
• Saves selections per device session, preventing unnecessary changes.

This extension fixes gaps in audio routing behavior by allowing users to select an output device permanently, ensuring all alerts play on the right device every time.

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✨ Features

✔️ Allows users to select an audio output device
✔️ Uses device label matching only, avoiding unstable deviceId changes
✔️ Plays alerts automatically when an incoming event is detected
✔️ Includes a test sound button to verify correct routing
✔️ Remembers your selection even if the system audio setup changes

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⚙️ Installation

1. Unzip the extension

   • Download the extension
   • Unzip the downloaded file to a directory where it won't be accidentally deleted

2. Load the unpacked extension in Chrome:

   • Open chrome://extensions/
   • Enable Developer Mode (top right corner).
   • Click "Load Unpacked".
   • Select the folder containing manifest.json.

3. Grant permission to access audio devices:

   • Click the extension icon in Chrome.
   • Click "Grant Access" if required.

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🚀 How It Works

1️⃣ Device Selection (popup.js)

• The popup displays all available audio output devices.
• When a user selects a device:
• Its label is stored in chrome.storage.local (NOT deviceId or groupId).
• On playback, the extension matches the label to the latest available device.

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2️⃣ Playing Alerts (content.js)

• Monitors incoming browser events (like engagement notifications).
• Fetches the latest audio devices before playing each alert.
• Uses setSinkId(deviceId) to ensure playback happens on the selected output.

📧 Interprocess Communication

• popup.js → Sends selected device label to content.js.
• content.js → Monitors for storage updates and ensures dynamic switching.

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🔄 Updating The Extension

If you make changes:

1. Go to chrome://extensions/
2. Click "Reload" on your extension and your browser window.

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🛠️ Troubleshooting

❌ "Extensions cannot access audio devices"

Fix: Navigate to chrome://settings/content/sound and allow sound playback. Note: This has to be enabled on the Chrome Extension level, not the page level. Right click on the extension icon and select "View Web Permissions".

❌ No devices appear in the dropdown

Fix:

1. Ensure an audio output device is connected.
2. Click "Grant Access" to allow device enumeration.
3. Reload the extension.

❌ Alert sounds do not play on the selected device

Fix:

1. Open Developer Console (Ctrl + Shift + J / Cmd + Option + J).
2. Run: navigator.mediaDevices.enumerateDevices().then(console.log);- Ensure the intended output device appears.
3. Verify saved selection: chrome.storage.local.get(["selectedDeviceLabel"], console.log);4. Confirm setSinkId support: let audio = new Audio(""); audio.setSinkId("your_device_id").then(() => audio.play());

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📜 License

MIT License.

Made with ❤️ and ☕ for better audio routing!