`AddGaussianSNR`

Added in v0.7.0

The AddGaussianSNR transform injects Gaussian noise into an audio signal. It applies a Signal-to-Noise Ratio (SNR) that is chosen randomly from a uniform distribution on the decibel scale. This choice is consistent with the nature of human hearing, which is logarithmic rather than linear.

SNR is a common measure used in science and engineering to compare the level of a desired signal to the level of noise. In the context of audio, the signal is the meaningful sound that you're interested in, like a person's voice, music, or other audio content, while the noise is unwanted sound that can interfere with the signal.

The SNR quantifies the ratio of the power of the signal to the power of the noise. The higher the SNR, the less the noise is present in relation to the signal.

Gaussian noise, a kind of white noise, is a type of statistical noise where the amplitude of the noise signal follows a Gaussian distribution. This means that most of the samples are close to the mean (zero), and fewer of them are farther away. It's called Gaussian noise due to its characteristic bell-shaped Gaussian distribution.

Gaussian noise is similar to the sound of a radio or TV tuned to a nonexistent station: a kind of constant, uniform hiss or static.

Input-output example

Here we add some gaussian noise (with SNR = 16 dB) to a speech recording.

Input-output waveforms and spectrograms

Input sound	Transformed sound

Usage example

from audiomentations import AddGaussianSNR

transform = AddGaussianSNR(
    min_snr_db=5.0,
    max_snr_db=40.0,
    p=1.0
)

augmented_sound = transform(my_waveform_ndarray, sample_rate=16000)

AddGaussianSNR API

min_snr_db: float • unit: Decibel: Default: 5.0. Minimum signal-to-noise ratio in dB. A lower number means more noise.
max_snr_db: float • unit: decibel: Default: 40.0. Maximum signal-to-noise ratio in dB. A greater number means less noise.
min_snr_in_db: float • unit: Decibel: Deprecated as of v0.31.0. Use min_snr_db instead
max_snr_in_db: float • unit: decibel: Deprecated as of v0.31.0. Use max_snr_db instead
p: float • range: [0.0, 1.0]: Default: 0.5. The probability of applying this transform.