Compute and plot the autocorrelation of the voiced section for kmax =250. You can modify the example code above to do this. Label your x-axis as ‘Lag (in samples)’.
Notice the following in your plot of the autocorrelation: the autocorrelation has the highest peak for zero lag (k=0). This is a necessary property of all autocorrelations. Then the autocorrelation has strong positive peaks at equal distances to the left and right of the zero lag point.