A simple Firefox extension to test whether you're wearing your headphones or earphones correctly. Verify that the left channel is in your left ear and the right channel is in your right ear.
Features
Test left and right audio channels independently
Generates a clean 440Hz (default) sine wave tone
Visual feedback showing which channel is playing
Simple, intuitive interface
Interface supports both light and dark themes
Settings view allows setting theme, volume, and frequency of the tone
