The range  of values.
Yeah that 's why uh people used these lifters were inverse variance weighting lifters basically that makes uh uh Euclidean distance more like uh Mahalanobis distance with a diagonal covariance when you knew what all the variances were over the old data.
Mm - hmm. Mm - hmm. Hmm.
What they would do is that they would weight each coefficient by inverse of the variance. Turns out that uh the variance decreases at least at fast , I believe , as the index of the cepstral coefficients. I think you can show that uh uh analytically.