how to find the bandwidth of a signal

i have a audio signal ,I want to know the bandwidth because its specgram has artefacts i think it may be due to the sample rate.

Answer 1

[Daniel Shub]

For all but the simplest cases the term bandwidth is ambiguous. You probably want to look at the long-time Fourier transform instead of the short-timer (i.e., spectrogram). Assuming your audio signal is single channel and called x

plot(20*log10(abs(fft(x))))

From there you might be able to define the lower and upper frequency bounds of your signal.

[Mike]

Hi, i am looking for the bandwidth of this signal: f = (sin(2*pi*697*t) + sin(2*pi*1633*t))/2;

Can i use the same way: plot(20*log10(abs(fft(f)))) to define the lower and upper frequency bounds of my signal? Does the y axis represent the frequency values?

[krishna Chauhan]

No you need to make y axis as freq axis by multiplyinh time scale by Fs/N.What is the numerical BW here in your case?

You can varify using FFT by subtracting lowest freq from highest freq, I am not sure.

Answer 2

[Amir Tari]

Hi , I think Bandwidth is defined only for systems not signals

[Walter Roberson]

No, signals as well.

https://en.wikipedia.org/wiki/Bandwidth_(signal_processing)