Noise Type Identifier
Capture ambient noise with your microphone, run an FFT, and classify the dominant type from its spectral shape — hum, buzz, hiss, rumble, rattle, broadband or pure tonal — then see a likely source (electrical, mechanical, airflow or structural) with practical remediation tips.
ℹ What’s reliable vs. what’s a guess. The type is read from the spectral shape (slope, tonal peaks, 50/60 Hz content) — that is calibration-independent and trustworthy with the same mic and setup. The source suggestion is a heuristic starting point, not a diagnosis. Any level shown is an uncalibrated estimate from a consumer mic — not a certified dB SPL and not legal/complaint evidence. Keep automatic gain control and noise suppression OFF (this tool requests a raw stream) or the reading is meaningless. A consumer mic also rolls off at the extremes and generally cannot capture true infrasound (<20 Hz). Audio is analysed live and never recorded or uploaded.
Microphone
Verdict
Live spectrum (log frequency)
Optional: calibrate the level (shared)
Calibration is optional and only affects the rough SPL estimate (marked *). Classification works without it. The offset is stored locally and shared with every Noise Analysis tool, so you only calibrate once.
How It Works
When you press Start, the tool opens your microphone requesting a raw stream with automatic gain control, noise suppression and echo cancellation off (the browser or OS can still override this) and feeds it into a Web Audio FFT analyser. Every frame it measures the shape of the spectrum rather than just how loud it is — and shape is what tells different noises apart.
Three calibration-independent features do most of the work. The spectral slope (in decibels per decade of frequency) says whether energy falls toward the highs (rumble, pink-ish), rises toward the highs (hiss), or stays flat (broadband/white). A tonality measure and the prominence of the strongest peak above the spectral median tell whether the sound is a narrow tone (hum, pure tonal) or harmonic-rich (buzz). The crest factor of the waveform — peak versus RMS — flags intermittent, spiky rattle against a steady drone. Finally the tool measures how much energy sits within a couple of hertz of 50/60 Hz and their harmonics (100/120, 150/180 Hz), the fingerprint of mains-related hum.
From those features it picks the best-matching type and shows a rough shape-match percentage. It then maps the type to a likely source category: a 50/60 Hz family points to electrical (transformer, LED driver, ballast, ground loop); a tonal mid-frequency sound with harmonics to mechanical (fan, motor, bearing); rising high-frequency hiss to airflow (HVAC, vents); and broadband low-frequency rumble to structural (traffic, building plant). That source line is a heuristic, not a diagnosis — the honest way to confirm it is to switch a suspected source off and watch the spectrum change, since a before/after comparison with the same mic is genuinely meaningful even when the absolute level isn’t calibrated.
The optional calibration turns the relative dBFS level into a rough dB SPL estimate. Read the current level on a real sound-level meter (or a calibrated phone app), type that number in, and the tool stores the difference as an offset. That offset is shared across every Noise Analysis tool via your browser’s local storage, so you calibrate once. Even calibrated, the estimate is approximate and is not a substitute for a Type 1/2 meter or valid as legal evidence.