20 Hz – 20 kHz test tones
Tone generator
Pick a frequency and a waveform and press Play. It starts quietly and fades in and out, so turn your device volume down first and raise it slowly.
Sine · volume 20 % (−34 dBFS) · both channels
Start with your device volume low, especially in headphones, and stop if a tone is uncomfortable or your ears ring. Very high tones can be inaudible to you but still loud to children and pets. Press Esc to stop any sound.
Using the tone generator
Drag the slider for a rough frequency, then type an exact value or use the ÷2 and ×2 buttons to jump an octave. The pill above the waveform names the nearest musical note (A4 = 440 Hz) and how many cents away it is. Changes while a tone is playing glide smoothly instead of clicking.
Sine is a pure tone with no overtones, the right choice for hearing a single frequency or finding a rattle. Square, triangle and sawtooth add harmonics and sound buzzier. The volume is matched across shapes by RMS level, so switching from sine to square does not jump in loudness, and the top setting stays 6 dB below full scale.
The sweep glides from one frequency to another, spending equal time on each octave. Play it at low volume to find buzzing panels, check where a small speaker stops producing bass, or hear roughly where your own high-frequency hearing fades. Left and Right check that each speaker or earbud is wired correctly. The WAV download saves the current tone as a 44.1 kHz, 16-bit stereo file with short fades at both ends.
Laptop and phone speakers rarely reproduce much below 100 Hz, and for many adults hearing above about 15 kHz fades with age. That is common, and this page is not a hearing test; if you are worried about your hearing, see an audiologist.
Questions
Why can I not hear the highest or lowest tones?
Small speakers cannot move enough air for deep bass, and many headphones roll off above 16 kHz. Hearing also loses high frequencies with age. Before turning the volume up for a tone you cannot hear, try another pair of headphones, because the tone may be playing loudly at frequencies your gear or ears do not pass.
Is the sound generated online?
No. Every tone is calculated in your browser with the Web Audio API and goes straight to your speakers. The WAV file is built on your device too; nothing is uploaded.
What does −34 dBFS mean next to the volume?
It is the tone's level below the loudest signal your device can output, 0 dBFS. How loud that is in the room depends on your system volume, amplifier and speakers, so the same setting can be quiet on a laptop and very loud in headphones.