AE2M31ZRE/RAT seminar - Task No. 8a
GMM-based speaker verification
- GMM-based speaker verification
- Compute the matrix of MFCC for the utterances S0-S9 from
the corpus recorded at the first seminar same way as it was done at
last seminar, see VQ-based speaker identification.
- Compute GMM models of cepstrum variability for your own voice using the function gmdistribution.fit (example of its usage is
in gmm_example.m and in the previous seminar for vowel classification).
- Use number of mixtures m=4.
- Compute cepstrum of utterances of 2 different speakers (i.e. for your voice and a voice of other speaker). Do not use same utterances as for the training of GMM (i.e. use utterances Z0-Z9 from recorded database).
- Using MATLAB function pdf compute log-likelihoods for all short-time frames of analyzing speakers.
- 1st checked results: Display:
- all short-time values as well as the mean of the score computed
on the basis of emitted logarithmic likelihood for all test
utterances for your own voice,
- short-time values as well as the mean of the score test
utternaces for other speaker.
- the result of verification for other speakers.
- Improved GMM-based speaker verification
- Repeat above realized computation for extended feature vector
use 20 MFCC coefficients without c.
- 2nd checked result: Display:
- short-time values as well as the mean of the score for your
and other voice in the case when extended feature vector of 20
MFCC coefficients is used.
- Extended feature vector by differential
features (i.e. numeric estimation of the 1st derivative of the order 2
computed from 2 neighbouring frames).
Use the following function diffceps
for the estimation of delta features.
- 3rd checked result: Display:
verification results using the same procedure realized before for
the features vector extended by delta parameters.
- On-line GMM-based speaker verification
- In the case of off-line and on-line verification try to apply
cepstral normalization (CMN). To realize cepstral mean
subtraction in the utterance, use to following function
- 4th checked result::
- Working on-line speaker verification with possible choice of CMN
application using GMM modelling.