I am using pwelch function of Matlab which returns the power spectral density (PSD) estimate. This got me confused about DFFT size and Windows size. Here my code:

% N = 94144
% fs = 44100
segmentLength = 4410; % window size
overlappedSamples = 2205; %  50% overlap
[pxx3,f3] = pwelch(data,segmentLength,overlappedSamples,segmentLength,fs); % in this case pxx3 returns vector of 2206 values

% second parameter: the length of the Hamming window to be used 
% fourth parameter: number of FFT points to be used

So here my Window size is 4410 and I am using 4410 DFFT points but I am still confused about the difference between the two? How come if I change the overlap from 50% to 0% I still have 2206 values in pxx3 vector?

Apologize in advance for any possible obvious explanation that I missed.


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