Please, i'm doing a study about the noise generated in engines, i have inserted the sound in the matlab. I have turned it to the frequency domain and now i would like to compare this signal with another signal generated by a motor defective. how do

Please, i'm doing a study about the noise generated in engines, i have inserted the sound in the matlab. I have turned it to the frequency domain and now i would like to compare this signal with another signal generated by a motor defective. how do

Answer 1

[Image Analyst]

See pwelch() in the Signal Processing Toolbox: http://www.mathworks.com/help/signal/ref/pwelch.html?s_tid=srchtitle

The spectrogram http://www.mathworks.com/help/signal/ref/spectrogram.html may also be useful if you want the spectrum at each point in time.

Answer 2

[Star Strider]

My first approach would be to divide the fft of the defective engine by the fft of the normal (reference) engine to see how the frequencies differ. Ideally, the sound of both engines are recorded when they are running at the same speed (RPM) and the signal recorded at the same sampling frequency, gain, and other parameters.