Skip to content

See sound

Pick a sound, or turn on your microphone. Time runs left to right, pitch runs bottom to top, and the brighter a spot is the louder that pitch was at that moment. Point at the picture to read exact numbers.

Pick a sound

One note at 196 Hz, with overtones stacked evenly above it. That stack is why it sounds like a guitar and not a flute.

The sound wave
↑ Pitch
quietloud
20 Hz
50 Hz
100 Hz
200 Hz
500 Hz
1 kHz
2 kHz
5 kHz
10 kHz
20 kHz
0 s → 3.00 sTime →
Time
Point at the picture
Pitch
Loudness

Detail

Balanced · 2048 samples

This is the tradeoff, and it is the whole lesson. Sharper timing blurs the pitch; finer pitch blurs the timing. Nothing makes both sharp at once.

Sharp timingFine pitch
Each column covers
42.7 ms
Pitches closer than this merge
23.44 Hz

View

Linear is what the FFT returns, log matches how pitch is heard, mel matches how hearing spaces it out.

Everything else
Window size2048 samples
1288192
Bin spacing
23.44 Hz
Window duration
42.7 ms

How many samples go into one column. This is what the detail control sets.

Overlap75 %
0 %87 %
Hop
10.7 ms
Bins
1025

How much each window shares with the last one. It sets the hop.

Dynamic range-90 dB → −10 dB

Which slice of dB the colour ramp is stretched across.

Window function

Hann — cosine taper, the usual choice

Cutting a signal off abruptly invents frequencies that were never in it — leakage. A taper is how that is kept down.

Sample rate
48.000 kHz
Nyquist
24.00 kHz
Bins
1025
Columns
0