Sound Analyzer.
Measure a sound. Find its frequencies. Compare what changed.
Listen closer.
Your microphone or an audio file. Everything is processed here, in your browser.
Files up to 60 seconds / 20 MB. Stereo analysis uses channel 1; playback keeps both channels.
Ready. Your microphone is off.
Optional recording
Recording is optional and stays in this browser. Download a clip if you want to keep it.
Playback does not move the charts: imported and recorded clips show a whole-clip analysis.
Measurement settings & microphone details
Hann window · no spectral smoothing · DC removed. Larger windows separate nearby tones better but cover more time. Change settings before starting a new measurement.
Audio is processed locally in this browser. Microphone hardware or browser processing can affect measurements.
The sound, made visible.
Start a measurement to see numerical results.
Waveform
Digital amplitude / timeFrequency spectrum
Tonal dBFS / frequency (Hz, log scale)Spectrogram
Frequency (Hz, log scale) / elapsed timeLive view uses sampled frames, not continuous recording. File view includes every analysis frame. Dark areas are quieter; bright bands show stronger frequencies.
Significant peaks
Up to six separated peaks above a conservative relative threshold. These are spectral features, not a diagnosis.
- No measurement yet.
Frequency-band energy
Share of total AC spectral power. Bands below 20 Hz or above 20 kHz are excluded, so values may total less than 100%.
- No measurement yet.
Before. After. Side by side.
Capture a stopped live frame or a whole-file average into A and B. Use the same microphone, position, gain, FFT settings and operating conditions.
No snapshots saved. Snapshots stay in this tab and are lost on reload.
Pink: A · Blue: B · tonal dBFS / Hz (log scale)
| Measurement | A | B |
|---|
A little context goes a long way.
Waveform: how the signal moves
The waveform shows digital amplitude over time. Live input shows the latest short window; a file shows the entire clip. Flat sections are quiet. Peaks near ±1 can indicate clipping.
Spectrum: what frequencies are present
The spectrum separates the sound into frequency bins. The strongest peak is not always the fundamental tone or a machine’s rotation rate. Closely spaced tones may blend together; larger FFT sizes help separate them. Peak estimates can fall between bins, but that does not create extra resolving power.
Spectrogram: what changes over time
Time runs left to right, frequency rises from bottom to top. A steady tone makes a horizontal band. A changing tone bends. Short impacts spread across frequencies. File spectra average power over the clip; a brief event may be clearer in the spectrogram than in the average.
Digital level is not sound pressure
Levels use dBFS, referenced to digital sample amplitude 1. A full-scale sine has about −3.01 dBFS RMS and 0 tonal dBFS at its frequency. This is not a calibrated dB SPL meter. Microphone response, automatic gain, placement and browser resampling affect the result.
Useful measurements, honest limits
This tool measures signal levels and frequency content. It cannot establish whether a bearing, engine, compressor or appliance is healthy. Use the same recording conditions for comparisons. Keep your phone and yourself clear of moving, hot or live parts.
Your sound stays here
Audio is decoded and analyzed locally. This page includes no analytics or audio upload service. Recording formats depend on your browser. Snapshots are held in memory only; use Download clip to keep a recording. Clear clip or leave this page to release it.
Working with an engine? Try the Engine Sound Analyzer for live snapshots, harmonics and optional RPM references. Continue with WorkshopGirl’s practical tutorials or the digital workbench.