Tone Generator

Play a pure tone at any frequency between 20 Hz and 20 kHz. Start quiet and raise the level slowly.

Protect your hearing. This tool starts at a low level on purpose. Raise your system volume gradually, and be especially careful above 8 kHz, where a tone can be far louder than it sounds.

Frequency sweep

Instead of one frequency at a time, glide from one bound to the other and listen for where output starts, stops, or changes character.

Logarithmic is the default because pitch is perceived by ratio, not by difference: the step from 100 Hz to 200 Hz is heard as the same distance as the one from 5 kHz to 10 kHz. A linear sweep crosses the entire bass range in its first one percent and then spends nearly all its time in the treble, which is useful when you are reading a frequency-response plot and almost useless when you are listening.

What a tone generator is for

A pure tone contains a single frequency and nothing else, which makes it the cleanest way to ask a piece of hardware one question at a time. Music is a poor diagnostic because a rattle at 60 Hz is buried under everything else happening at once.

Reading the result

Hearing nothing is a result, not a failure. Most laptop and phone speakers produce nothing usable below about 150 Hz, and adult hearing commonly stops well below 20 kHz. The readout always shows the frequency being played, so you can note exactly where output begins and ends.

Not sure where the problem is? Run the full sound check: six quick questions, and one summary that points you at the right tool.