LowPassFilter

Added in v0.18.0, updated in v0.21.0

Apply low-pass filtering to the input audio of parametrized filter steepness (6/12/18... dB / octave). Can also be set for zero-phase filtering (will result in a 6 dB drop at cutoff).

LowPassFilter API

min_cutoff_freq: float • unit: hertz

Default: 150.0. Minimum cutoff frequency

max_cutoff_freq: float • unit: hertz

Default: 7500.0. Maximum cutoff frequency

min_rolloff: int • unit: Decibels/octave

Default: 12. Minimum filter roll-off (in dB/octave). Must be a multiple of 6 (or 12 if zero_phase is True)

max_rolloff: int • unit: Decibels/octave

Default: 24. Maximum filter roll-off (in dB/octave) Must be a multiple of 6 (or 12 if zero_phase is True)

zero_phase: bool

Default: False. Whether filtering should be zero phase. When this is set to True, it will not affect the phase of the input signal but will sound 3 dB lower at the cutoff frequency compared to the non-zero phase case (6 dB vs. 3 dB). Additionally, it is twice as slow as the non-zero phase case. If you absolutely want no phase distortions (e.g. want to augment an audio file with lots of transients, like a drum track), set this to True.

p: float • range: [0.0, 1.0]

Default: 0.5. The probability of applying this transform.

Source code

audiomentations/augmentations/low_pass_filter.py