How to extract specific MFCC from .wav files?

When I use the "audioFeatureExtractor" to extract MFCC, since there are 13 MFCC features, I am not sure how to use the setExtractorParams function to pick specific MFCC features? For example, MFCC 1, 4 , 6, and 11.

aFE = audioFeatureExtractor("SampleRate",fs, ...
    "mfcc",true);

idx = info(aFE) % output below.

setExtractorParams(aFE,"mfcc",) % not sure how to pick the MFCC features. I don't need all of them.

idx = struct with fields:

mfcc: [1 2 3 4 5 6 7 8 9 10 11 12 13]

Answer 1

[jibrahim]

Hi Ibrahim,

Here you go:

setExtractorParams(aFE,"mfcc","NumCoeffs",11)

[hp]

Y NumCoeffs is 11?plz elaborate the answer

[jibrahim]

Sorry, let me clarify.

You use setExtractorParams to set the number of MFCC coefficients to compute. NumCoeffs is a scalar value. This function does not enable you to "pick" specific coefficients But that is easy to do by simply indexing into the output of the audioFeatureExtractor.

[audioIn,fs] = audioread('speech_dft.wav');
aFE = audioFeatureExtractor("SampleRate",fs, ...
    "mfcc",true);
% Set the max number of mfccs to compute
setExtractorParams(aFE,"mfcc","NumCoeffs",11)
features = extract(aFE,audioIn);
% Extract the coefficients you are interested in
mfccs = features(:,[1 4 6 11])