440 Hz
A4
20 Hz20 kHz
Waveform
Presets
About
The Tone Generator produces pure audio tones using the Web Audio API. Choose from sine, square, sawtooth, and triangle waveforms at any frequency between 20 Hz and 20 kHz. It is useful for hearing tests, tinnitus masking, speaker testing, music tuning (440 Hz reference tone), and audio engineering experiments.
How to use
- 1 Use the slider or type an exact value to set the frequency.
- 2 Select a waveform: Sine (pure tone), Square (buzzy), Sawtooth (bright), or Triangle (soft).
- 3 Adjust the volume slider and toggle the mute button as needed.
- 4 Press the Play button to start the tone. Press Stop to silence it.
- 5 Use the preset buttons to jump to common test frequencies.
- What is a sine wave tone used for?
- A sine wave produces the purest possible tone — a single frequency with no harmonics. It is used as a reference tone for tuning instruments (440 Hz = concert A), calibrating audio equipment, conducting hearing tests, and testing speaker frequency response. Because it contains no harmonics, any distortion or resonance is immediately apparent.
- What is the difference between sine, square, sawtooth, and triangle waveforms?
- A sine wave contains only the fundamental frequency — pure and smooth. A square wave contains the fundamental plus all odd harmonics (3rd, 5th, 7th...) — bright and buzzy, like a clarinet. A sawtooth wave contains all harmonics (odd and even) — very bright and brash, like a violin bow. A triangle wave has odd harmonics that fall off faster — softer than square, resembling a flute.
- Can I use this as a hearing test?
- Yes. Play tones at different frequencies to check your hearing range. Human hearing spans roughly 20 Hz to 20,000 Hz, though the upper limit decreases with age — many adults over 40 cannot hear above 14,000–16,000 Hz. Use headphones for best results, keep the volume low, and start at mid-frequencies before testing the extremes. This is not a medical test — consult an audiologist for clinical hearing assessment.