I have a sound file with noise with Fs = 44100Hz, How can I choose cut off frequency and how to design a filter to remove noise

sound signal matrix size 44975*2 I have a sound file with noise with Fs = 44100Hz, How can I choose cut off frequency and how to design a filter to remove noise. supress noise atleast 20Db

Can anybody help on this

Answer 1

[Star Strider]

To find the signal and noise frequencies, use the fft function. The documentation for fft has all the information you need in the code between to first two figures.

After you decide what part of your signal are valid data and what parts are noise, design a bandpass filter with a low-frequency cutoff to exclude the low-frequency noise and baseline drift, and a high-frequency cutoff to exclude the noise. Choose the stopband to produce the best result. I usually find that to be [0.5, 1/0.5]*Wp to [0.8, 1/0.8]*Wp*, where ‘Wp’ is the passband vector. The general filter design procedure I use is described here.