Tone Generator

Play a pure tone at any pitch from 20 Hz to 20 kHz. Start quiet, then turn it up slowly.

Look after your ears. Tones start quiet on purpose. Turn your volume up slowly, and take extra care above 8 kHz, where a tone can be much louder than it sounds.

Frequency sweep

Instead of one pitch at a time, glide smoothly from one to another, and listen for where the sound starts, stops or changes.

Logarithmic is the default because that's how we hear pitch: the jump from 100 Hz to 200 Hz sounds as big as the jump from 5 kHz to 10 kHz. A linear sweep rushes through all the bass in the first second or so, then spends nearly all its time in the treble. That's handy if you're reading a frequency chart, but not much use when you're listening.

What a tone generator is for

A pure tone is a single pitch and nothing else, which makes it the simplest way to ask your equipment one question at a time. Music is no good for this: a rattle at 60 Hz gets buried under everything else that's going on.

Hearing nothing?

That's a result, not a failure. Most laptop and phone speakers can barely play deep bass at all, and most adults stop hearing high tones well before 20 kHz. The readout always shows the pitch that's playing, so you can note exactly where the sound starts and stops.

Not sure where the problem is? Run the full sound check. It's six quick questions, and at the end it tells you which tool to use next.