Standards compliant
ANSI S1.11-2004 filter banks and IEC 61672-1:2013 weighting, verified by 180+ tests in CI.
phonometry
Professional acoustic analysis in Python — fractional octave banks, A/C/Z weighting, time ballistics, Leq and statistical levels.
Five architectures
Butterworth, Chebyshev I/II, Elliptic and Bessel — all as stable SOS cascades with −3 dB points on the band edges.
Real-time ready
Stateful block processing, vectorized multichannel, multirate decimation.
Sound level metering
A/C/Z weighting, Fast/Slow/Impulse ballistics, Leq, LAeq, L10/L50/L90 and octave spectrograms.