Glottal closure instant detection using Lines of Maximum Amplitudes (LOMA) of thewavelet transform

The Lines Of Maximum Amplitude (LOMA) of the wavelet transform are used for glottal closure instant detection. Following Kadambe & al. (1992), the wavelet transform modulus maxima can be used for singularity detection. The LOMA method extends this idea. All the lines chaining maxima of a wavelet transform across scales are built. Then a back-tracking procedure allows for selection of the optimal line for each pitch period, the top of which indicates the GCI. The LOMA method is then evaluated by comparing its results to the DYPSA (Naylor & al.) algorithm, with the option of using inverse filtering as preprocessing. The LOMA method compares favorably to DYPSA, particularly on accuracy. One of the advantage of the LOMA method is its ability to deal with variations in the glottal source parameters.