Having been asked a really pertinent question about the previous post’s ( Interpolation ) description, this post is an attempt to answer it. The question: “If zero padding is the technique to be used in interpolation, and the inserted samples are zeroes, how does this work? Where do the intermediate sample values come from?” The answer to this question is, that the even though the inserted samples are zero, the interpolation filter is designed in such a manner that IT provides the missing samples. It interpolates between the available “true” samples of the old data stream and the new inserted zeroes to come up with the in – between samples. Please visit our website at http://www.signalpro.biz and click on the ” free articles …” menu item to access a broader description of multi-rate sampling.