Tone Generator & Water Eject — Free, Browser-Based
A precise Web Audio tone generator: sweep 20 Hz to 20 kHz on a logarithmic slider, pick a waveform, pan to the left or right speaker, and run a pulsed 165 Hz water-eject cycle to push water out of phone or laptop speakers. No app, no sound files — pure synthesis on your device.
Private by design. Tones are synthesized locally with the Web Audio API — no microphone access, and nothing is sent to a server.
How to generate a test tone or eject water from a speaker
- Set a frequency. Drag the logarithmic slider from 20 Hz to 20 kHz, type an exact value in hertz, or tap a preset like 440 Hz (A4) or 1 kHz.
- Pick waveform and volume. Choose sine, square, triangle, or sawtooth. Keep volume below 50% to start — high frequencies can be uncomfortable at full level.
- Play and adjust live. Press Play. Frequency, volume, waveform, and channel all update smoothly while the tone plays — no clicks or pops.
- Run Water Eject for wet speakers. Set volume high, point the speaker downward, and press Start eject cycle. Pulsed 165 Hz bursts run for about 30 seconds with a progress bar.
Use Cases
Frequently Asked Questions
Does the water eject really work?
It uses the same principle as the Apple Watch eject feature: low-frequency bursts (165 Hz) physically vibrate water droplets out of the speaker cavity. Run it 2–3 times with the speaker facing down for best results.
Is anything recorded or uploaded?
No. Tones are synthesized locally with the Web Audio API oscillator. The tool does not use your microphone and sends nothing to any server.
How do I test my left and right speakers?
Use the Channel buttons — Left plays the tone only on the left channel, Right only on the right (via a stereo panner). If sound comes from the wrong side, your speakers or headphones are swapped.
What frequency should I use for a hearing check?
Try the presets in order: 10 kHz is audible to most adults, 15 kHz typically fades for people over ~40, and 17.5 kHz is usually only heard by teenagers. This is a fun screening, not a medical test.
Why can I not hear anything above 15 kHz?
Age-related hearing loss (presbycusis) reduces high-frequency sensitivity from early adulthood, and some laptop speakers roll off before 20 kHz. Try headphones at moderate volume before concluding anything.
Which waveform should I pick?
Sine is a pure single frequency — best for hearing tests and water eject. Square and sawtooth add harmonics, which makes them louder-sounding and useful for testing buzz or rattle in speakers.
Test-frequency cheat sheet — what each preset is for
Every preset on this page has a specific diagnostic purpose. Here is what each frequency tells you about your speakers or your hearing.
| Frequency | What it is | What to listen for |
|---|---|---|
| 165 Hz (pulsed) | Water-eject frequency used by the Apple Watch | Water droplets visibly vibrating out of the speaker grille |
| 440 Hz | Concert pitch A4 — the orchestra tuning reference | A clean, steady reference for tuning instruments by ear |
| 1 kHz | Standard audio-engineering reference tone | Level calibration; should sound identical on both channels |
| 10 kHz | Upper-mid treble | Audible to most adults; dullness suggests speaker or hearing roll-off |
| 15 kHz | High treble | Typically inaudible past age ~40; also tests tweeter response |
| 17.5 kHz | Near the top of human hearing | Usually heard only by teenagers and young adults |
- Keep volume moderate: prolonged exposure above 85 dB damages hearing at any frequency, and high-frequency tones can be louder than they feel.
- Laptop and phone speakers often cannot reproduce 20–60 Hz at all — use headphones or monitors when testing the lowest octave.