Explore how filters shape sound in the frequency domain.
Record your voice (or upload a WAV file), choose a filter, adjust the
cutoff frequency, and click Apply Filter to see the
waveform and spectrogram transform in real time.
Time Domain Waveform
Upload or record audio — waveform appears automatically.
Spectrogram
Spectrogram appears automatically after recording.
Constellation Map
Record or upload audio, then select view mode and click Generate Constellation to visualize spectral peaks.
Low-pass Filter
A low-pass filter attenuates frequencies above the cutoff
while letting lower frequencies through. In audio this makes voices
sound muffled or distant — the same effect as speaking through a wall
or into a pillow.
How it works: A Butterworth filter (order 5) is
computed in the frequency domain and applied as a cascade of
second-order sections (SOS) for numerical stability. The
roll-off is −30 dB/octave beyond the cutoff.