Tone Generator

What it's for

Make a test tone or noise. A steady tone at a known pitch is useful for checking speakers and headphones, tuning, finding a rattle, or matching the pitch of tinnitus; a glide from low to high finds the frequencies a speaker or room struggles with; and noise helps with masking sound or testing levels.

For example, when one side of your headphones sounds weaker, play a 1000 Hz sine wave and compare each side, then try a glide from 20 to 20000 Hz to hear where each stops.

How to use it

Choose the Sound: a sine, square, triangle or sawtooth wave, or white, pink or brown noise. For a wave, give the Frequency in hertz or as a note such as A4, C#5 or Eb3 (A4 is 440 Hz), and if you like a Glide to frequency or note. Glide sets whether the pitch rises evenly as you’d hear it (each octave takes the same time) or evenly in hertz. The message names the nearest note to each frequency.

Set the length in Seconds and the Volume, then Play (tick Repeat until stopped to loop it) or Save as WAV. The sound, length and volume are remembered in this browser.

Example

Choose Sine wave, type A4 in Frequency and A5 in Glide to, and set Seconds to 3.

The message says 440 Hz is A4, gliding to 880 Hz is A5. Play sweeps up an octave over three seconds, and Save as WAV saves tone-440hz-880hz.wav.

Good to know

Start with the volume low, especially with headphones: high and very low tones can be louder than they seem, and some speakers can be damaged by long, loud tones. What you hear also depends on your speakers, which may not reproduce very low or very high frequencies at all.

Tones are made at 48,000 samples a second, so frequencies up to 24,000 Hz are possible, beyond most people’s hearing. Square and sawtooth waves at high frequencies carry some distortion.