Autocorrelation and Alignment

I have a speech signal with 18000 samples. Call this the original signal. Also, I have the same speech signal with a time delay. Now, the task I need to achieve is to auto correlate the signals and align the signal to the original signal time index.

Can you please help me with it. Thank you.

Answer 1

[Abhishek Gupte]

1. Use XCORR in the Signal Processing Toolbox to find the correlation between the two signals;

2. Find the index of the max value of the correlation output - n;

3. If L is the length of the two signals, the delay between the two signals is abs( n-L ).

[Dinesh Manohar]

Thank you.

Answer 2

[Dinesh Manohar]

I have an extended question pertaining to the same topic.

I have a signal say , x and I have another signal say y which is y= x(l:m), where min(size(x))<l<m< max(size(x)). That is , I have a part of the signal. Now, I correlated the function and plotted it. I got a max of the plot at some index and the plot gradually started decreasing over increase in time index. Now, as per your comment, it means to say that the signal y is correlated in that lag shown by the plot? Please help me in this regard.

Thank you.