Online Tone Generator

A pure tone is far more fatiguing than music at the same loudness, and your ears adapt to it quickly, so a level that seems fine at first can become harmful over several minutes. Set your system volume low, start this tool’s volume slider near the bottom, and raise it only until the tone is clearly audible. Be especially careful with headphones and with frequencies above 2 kHz, where the ear is most sensitive.

Square and sawtooth waves carry a lot of high-frequency energy, so they sound much louder than a sine at the same slider position. Switch waveforms with the volume turned down. Long, loud, high-frequency tones can also overheat small tweeters — if a speaker starts to sound strained, stop.

Every periodic sound can be described as a fundamental frequency plus a set of harmonics at whole-number multiples of it. The four waveforms here differ only in which harmonics they include and how strong they are:

Use a sine whenever the goal is to test a single frequency. With a square or sawtooth wave you are also hearing energy at 2×, 3×, 5× the displayed frequency, so a “100 Hz” sawtooth will still sound clearly on a speaker that cannot reproduce 100 Hz at all — the speaker is playing the harmonics.

A slow sweep through the audible range shows what a speaker can actually reproduce and exposes mechanical faults that music tends to hide. Use a sine wave throughout:

1. Set the frequency to 1 kHz and adjust the volume to a quiet, comfortable level. This is your reference.
2. Drag the slider slowly down towards 20 Hz. Note where the bass fades out. Laptop and phone speakers usually lose output somewhere between 150 and 300 Hz; good headphones and subwoofers continue well below 40 Hz.
3. Listen for buzzing, rattling or fluttering as you pass through the low range. A clean speaker produces only the tone. A rattle at one specific frequency is often a loose screw, grille or nearby object resonating rather than the driver itself.
4. Return to 1 kHz, then sweep up towards 20 kHz. Note where the tone disappears. That point is set by your hearing as much as by the speaker, so compare against a second pair of headphones if you want to tell them apart.
5. Listen for sudden jumps or dips in loudness on the way. Some unevenness is normal, especially in a room; a narrow frequency that is dramatically louder usually points to a room or enclosure resonance.

The slider is logarithmic, matching how we perceive pitch: each octave (a doubling of frequency) takes the same distance on the slider, so 20–40 Hz gets as much room as 10–20 kHz.

Young listeners can typically hear from about 20 Hz to 20 kHz. The upper limit falls steadily with age — a process called presbycusis — and with noise exposure. Many adults in their forties no longer hear much above 14–15 kHz, and by sixty, 10–12 kHz is common. A tone around 17 kHz is famously audible to most teenagers and few older adults.

To find your own upper limit, set a sine wave at a moderate volume, start at 8 kHz and step upwards until the tone vanishes, then come back down until it reappears. Repeat a few times; the average is a reasonable estimate. Bear in mind that consumer speakers and many headphones roll off above 15–16 kHz themselves, and that this is not a substitute for a hearing test. A real audiogram is measured with calibrated equipment at controlled levels in a quiet booth. If you notice a sudden change or a difference between ears, see an audiologist.

Many people with tonal tinnitus find it useful to identify its pitch, both to describe it to an audiologist and for sound-based therapies that rely on knowing the frequency. A careful approach:

1. Work in a quiet room with the volume set very low — the match should be just audible, never loud.
2. Use a sine wave. Tinnitus is usually closest to a pure tone.
3. Bracket first: compare 1 kHz, 4 kHz and 8 kHz to find the right region, then narrow down with the slider.
4. Check one octave above and below your best match. Octave confusion is the most common mistake in tinnitus matching — two tones an octave apart can feel surprisingly similar.
5. Take short breaks and repeat the match on different days; the perceived pitch can drift.

This tool cannot diagnose or treat tinnitus. Use the frequency you find as information to bring to a professional.

Western music uses twelve-tone equal temperament, in which every semitone is the same ratio — the twelfth root of two, about 1.0595. Twelve semitones make an octave, which doubles the frequency exactly. With A4 tuned to 440 Hz (the international concert standard), any note’s frequency can be calculated from its MIDI note number n:

frequency = 440 × 2^((n − 69) ÷ 12)

The tool uses the same formula in reverse to show the nearest note name next to the frequency. A semitone is divided into 100 cents; most listeners notice a difference of around 5 to 10 cents between two tones played one after the other.

For other octaves, double the frequency to go up one and halve it to go down one: A ranges from 27.5 Hz (A0, the lowest key on a piano) through 55, 110, 220, 440, 880 and 1,760 to 3,520 Hz (A7). The piano’s top note, C8, is 4,186 Hz.

Tuning reference for common instruments

Type the frequency into the input box, play the tone, and tune the string until the beating — a slow wobbling in loudness — disappears. The beat rate equals the difference between the two frequencies, so a wobble once per second means you are 1 Hz away.