SNR is often used to process audio signal, in this tutorial, we will introduce you how to compute it using python.

## What is SNR

SNR is called signal-to noise ratio, it is defined as:

As to Px, it can be computed as:

We can find the value of a clean singal SNR depends on the power of the noise signal. If the noise is changed, the SNR also be changed.

Often SNR is given in decibels (dB), it is:

It means:

If SNR_{dB} = 0dB, SNR = 1, P_{s}=P_{n}, the power of the clean signal is equal to the noise signal.

If SNR_{dB} > 0dB, the power of the clean signal is larger than the noise signal.

Moreover, P_{n} is also an estimator of the variance of the noise σ^{2}. Therefore, one could have also defined the signal-to-noise ratio as follows:

## How to compute SNR in python?

In order to compute SNR, we should get a clean signal and a noise signal.

You can view here:

https://github.com/hrtlacek/SNR/blob/main/SNR.ipynb