Spectrogram Analyzer
See sound as a picture: frequencies over time, with tap-to-analyze partials, ratios, and implied fundamentals.
What a spectrogram shows
A spectrogram plots time across the horizontal axis, frequency up the vertical axis, and energy as brightness. A sustained instrument note appears as a stack of bright horizontal lines: the fundamental at the bottom and its harmonic partials stepping up above it. Glissandi curve, vibrato ripples each line, and noisy or percussive sounds smear energy broadly rather than into clean lines. It is the most direct way to see what a sound is actually made of.
What the analyzer does
Import an audio file or record straight from the microphone, and the module computes a short-time Fourier transform and renders it as a zoomable heatmap. You control the analysis and the display:
- FFT size and overlap: trade time resolution against frequency resolution to suit transients or sustained tones.
- Dynamic range and brightness: set how many decibels map across the color ramp, and lighten or darken the display.
- Log or linear frequency: view octaves at equal spacing, or frequency at equal spacing.
- Pinch to zoom and drag to pan along the time axis to inspect a single event closely.
Tap to analyze partials
Tap anywhere on the heatmap to drop a crosshair and read the loudest peaks at that instant. Each partial shows its nearest pitch name, exact frequency in Hz, cents deviation, and relative level, and can be auditioned on its own. The module lists the interval ratios of the peaks relative to the lowest one, and searches for the implied fundamentals whose harmonic series would contain them: the same missing-fundamental reasoning the ear uses. Press play and a white line tracks the audio across the spectrogram as it sounds.
Who this is for
The Spectrogram Analyzer is for anyone who wants to look inside a sound: spectral composers checking the partial content of a sample, orchestrators studying how a chord's overtones stack, sound designers hunting resonances, and students connecting what they hear to what they see. To compute the overtone series from a single fundamental, use Harmonic Series; to explore the combination tones that emerge between several frequencies, use the Spectral Calculator.