Controlled signal
The tool generates the test inside your browser with a bounded app-level gain. Your operating-system and hardware volume remain separate.
Online Tone Generator
Use a controlled oscillator for functional checks, resonance hunting and signal-path setup. The generator starts quietly and caps its own master gain, but system volume still matters.
sine / -18 dB
Safety: Do not use this tool to test hearing limits. Stop immediately if a tone is uncomfortable or the device sounds strained.
Local by default
Output tests do not upload audio. Microphone tools request permission only when started and explicitly state what stays in memory.
SCOPE / 01
What this test checks
The generator creates a mathematically defined oscillator inside Web Audio. A sine wave isolates one frequency; square, triangle and sawtooth waves add different harmonic patterns. Repeating a tone helps locate a narrow rattle or signal-path dropout.
- Finding the frequency that triggers a speaker, cabinet or room resonance.
- Checking whether a signal path passes a known pitch without using a downloaded audio file.
- The requested digital frequency, waveform and app-level gain sent by the browser.
- Whether an audible buzz, dropout or rattle repeats at the same setting.
- Whether lowering level or bypassing EQ changes the unwanted sound.
- Flat frequency response, acoustic output level or hearing thresholds.
- Ultrasonic playback beyond the tool's 20 Hz–20 kHz safety boundary.
PROCEDURE / 02
How to run this test
Keep the level moderate and change one thing at a time so the result remains useful.
- 01
Set the frequency and waveform before pressing play.
- 02
Begin at the default reduced level.
- 03
Adjust frequency in small steps between playback runs.
- 04
Stop immediately if the sound is uncomfortable or the device distorts.
INTERPRETATION / 03
What your result means
Match what you heard or saw, change one variable, then use the linked check to verify the result.
| Observation | Likely cause | Next step | Retest |
|---|---|---|---|
| 01A rattle appears only around one narrow frequency. | A loose object, enclosure panel, port, desk or room surface may be resonating with that band. | Keep the level fixed, move nearby objects and repeat just above and below the problem frequency. | Check distortion causes |
| 02The tone fades gradually near the low or high extreme. | Driver capability, fit, room response and personal audibility normally limit extreme frequencies. | Do not compensate with a large volume increase; compare with a slower sweep at the same safe level. | Run a frequency sweep |
| 03Many frequencies sound rough or compressed. | An overloaded gain stage, heavy EQ, enhancement or damaged signal path may be producing broad distortion. | Lower every gain stage, bypass EQ and compare another output device before assuming a driver failure. | Troubleshoot distorted audio |
| 04A square or sawtooth wave sounds much brighter than sine. | Those waveforms intentionally contain strong harmonics above the displayed fundamental frequency. | Use sine for single-frequency diagnosis and reserve harmonic waveforms for signal-path experiments at reduced level. | Review the audible range |
VARIABLES / 04
Why results can vary
The generated signal stays controlled; the physical device, room and system path can still change what reaches you.
Waveform harmonics
Only sine represents a single frequency; the other waveforms distribute energy across predictable multiples of the fundamental.
Sample-rate conversion
The browser and operating system may resample Web Audio to the rate used by the selected output device.
Device and room response
Speakers, headphones, placement and surfaces can make equal digital levels sound very different by frequency.
Personal audibility
Not hearing an extreme tone does not identify whether the limit is the listener, level, device or room.
LIMITS / 05
Browser limits and safety
Online Tone Generator questions
What waveform should I use?
Use sine for clean single-frequency checks. Other waveforms contain harmonics and sound much brighter.
Can I enter frequencies above 20 kHz?
No. The control is bounded to the conventional audible range and many devices cannot reproduce its extremes.
Why can’t I hear 20 Hz?
Small speakers and headphones may not reproduce it audibly, and low-frequency perception depends strongly on level and seal.