Comparison with SPA and CLT

We now have three ways for computation of the MEL band analysis. In Section 5.2.3, we discussed the SPA-based implementation of MEL bank analysis, which is implemented by module software/module_mel_bank.m with method='spa'. In Section 5.2.6, we developed the CLT-based approach, which is the basis of software/module_mel_bank.m with method='clt'. These two modules compute the feature ${\bf z}={\bf A}^\prime {\bf x}.$ The ML method is implemented by software/module_mel_ml.m. The ML approach finds different features, ${\bf b}_{\rm ML}({\bf x})$. Therefore, head-to-head comparison of the J-function is not meaningful. We will revisit this question later in Chapter 11.