(i) Estimation of power spectrum: For analysis window. Here, the signal is passed through a Hamming window and the squared magnitude of FFT is taken as window.
(ii) Critical Band Analysis power spectrum is integrated within the critical band filter response.
(iii) Equal loudness pre-emphasis compensate for the non-equal perception of loudness at different frequencies.
(iv) Intensity loudness conversion log taken before integration. This compress the power spectrum.
(v) Auto-regressive model is used to smooth the spectrum.
Sr. |
MFCC |
PLP |
1. |
Calculates power spectrum |
Calculates power spectrum |
2. |
Integration of power spectrum using Mel filter bank |
Integration of power spectrum using Bark scale filter bank |
3. |
Pre-emphasis done before spectral analysis |
Pre-emphasis is done using equal loudness pre-emphasis curve |
4. |
Log is taken before integration for spectral compression |
Cube root of power spectrum is taken |
5. |
Take IDFT, get cepstral coefficients |
Take IDFT, get auto-correlation |
6. |
Spectral smoothing using cepstral transaction |
Auto-regressive model is used to smooth the spectrum |
7. |
No such option is present |
Coefficients converted to cepstral coefficient optionally |
8. |
Lifting is done to reduce variances of cepstral coefficients |
Lifting is done to reduce variances of cepstral coefficients |