Why my mel filters do not overlap on each other?

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cat0530
cat0530 2016-3-18
编辑： cat0530 2016-3-21
The 26 filters should overlap on each other. Could someone help me with this?
  1 个评论
Star Strider
Star Strider 2016-3-18
I’ve never used or designed MEL filters. I refer you to: Mel Frequency Cepstral Coefficient (MFCC) tutorial since it seems to be a comprehensive discussion. Compare your code with that discussion.

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采纳的回答

Rick Rosson
Rick Rosson 2016-3-20
编辑：Rick Rosson 2016-3-21
I think the problem is in the second elseif statement:
elseif (k>=f_range(m+1) && k<=f_range(m))
These two sub-conditions are mutually exclusive, so this condition is always false. As a result, the line after this condition, which creates the right half of the triangle, is never executed.
Please try:
elseif (k>f_range(m) && k<=f_range(m+1))
That being said, there are much easier and more efficient ways to create the filter bank in MATLAB, for example:
  • logical indexing
  • the tripuls function
  2 个评论
cat0530
cat0530 2016-3-21
Yes, you're right. I've changed the second statement and it works! Now the problem is that only 24 filters are shown in the graph instead of 26. I've tried changing the outer for loop but it says index out of bounds
Rick Rosson
Rick Rosson 2016-3-21
You need to create 2 extra points in f_range. So replace the following two lines:
%Need 26 points spaced linearly between minfreq and maxfreq
f_range = linspace(minMel, maxMel, nfilts);
with these two:
%Need 28 points spaced linearly between minfreq and maxfreq
f_range = linspace(minMel, maxMel, nfilts+2);

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更多回答（1 个）

Rick Rosson
Rick Rosson 2016-3-20
编辑：Rick Rosson 2016-3-20
Please review the tripuls function.
  2 个评论
Star Strider
Star Strider 2016-3-20
I’m not certain that will work. When I looked up the MEL filters (that are designed to emulate cochlear frequency responses), the pass-bands were intersecting and looked something like: ...XXXXX...

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