Pulse

Pulse is a browser-based focus and sleep audio tool tuned for open-ear and bone-conduction headphones.

Live demos:

• GitHub Pages: h3cz.github.io/pulse
• Vercel: pulse-public.vercel.app

It uses the Web Audio API to generate an ambient synth pad or process your own local audio file, then applies amplitude modulation and an optional bone-conduction EQ curve. The goal is simple: keep the open-ear headphones on, stay reachable, and still get focus audio that feels full enough to use.

Why I Built This

Open-ear headphones are great when you need to stay aware of your surroundings, but they can make focus audio sound thin. Pulse explores a browser-native way to improve that experience without paid infrastructure, native apps, or uploaded audio.

Features

• Focus modes: Deep Focus, Light Focus, Calm
• Sleep mode with low-frequency delta modulation
• BYO audio file support; files stay local in the browser
• Synth pad fallback with generated tones and noise bed
• Bone Conduction Mode that trims bass and boosts the open-ear midrange
• Session timers and guided frequency arcs
• Browser media-session support for hardware play/pause keys
• Optional mini-player via Document Picture-in-Picture in supported browsers
• Reduced-motion support
• Unit tests for frequency and EQ math

Tech Stack

Layer	Technology
Frontend	React 18, TypeScript, Vite
Styling	Tailwind CSS, Radix UI primitives
Audio	Web Audio API
Tests	Vitest

Architecture

The audio graph lives outside React render state:

• src/lib/pulse/engine.ts owns the Web Audio graph.
• src/hooks/useAudioEngine.ts is a thin React lifecycle wrapper.
• src/lib/pulse/states.ts holds pure frequency and EQ math.
• src/lib/pulse/programs.ts defines timed session arcs.

This keeps slider changes imperative and avoids rebuilding the graph during normal UI renders.

Local Setup

npm install
npm run dev

Build:

npm run build

Tests:

npm run test

Security And Privacy

• Uploaded audio files are not sent to a server.
• The app works with no backend.
• The public build ships with no remote analytics.
• Pulse is a focus/wellness utility, not a medical device.

See SECURITY.md.

Roadmap

• Add screenshots and a short demo GIF.
• Optionally wire consent-based analytics in a fork.
• Add manual QA notes for browser audio behavior.
• Package a small reusable PulseEngine demo page.

License

MIT