TinFade

TinFade generates continuous static in the browser and lets you carve it into a band. Two sliders set the lower and upper bounds anywhere between 20 Hz and 20 kHz, so you can sit the noise over whatever pitch you actually hear rather than playing broadband hiss at it. A third slider sets the level. Then you start the fade: the volume steps down gradually over a duration you choose, from one minute to an hour, defaulting to fifteen. If the ringing surfaces again there is a button that nudges the level back up ten per cent, and you carry on fading from there. Nothing to install and no account.

The fade is the whole idea. Masking noise is usually played at a fixed level, but attention drifts away from a sound that is slowly getting quieter, and you can generally end up lower than you started. The boost button exists so you can correct without stopping.

The other half is modulation — sine, triangle and sample-and-glide random shapes that can be attached to pan, volume or either frequency bound, so the noise drifts rather than sitting still. I have been deliberate about the wording throughout: TinFade is a sound tool, not a treatment, and the explicit disclaimer saying so is still on the to-do list.