Speech formant frequency estimation based on Hilbert-Huang transform

After being filtered with the band-pass filters with the centre-frequencies obtained by using the fast Fourier transform(FFT) analysis,speech data were decomposed into a set of intrinsic mode function(IMF) using empirical mode decomposition(EMD).The IMFs containing formant frequencies were then(identified) according to the energy maximum criteria,and their instantaneous frequencies and Hilbert spectra were calculated,and finally,the formant frequencies of speech data were efficiently determined.The results show that,compared with the conventional formant estimation methods,the method based on HHT not only can provide more clear descriptions of the non-linear and non-stationary characteristics of speech signals,but also gives the speech formant frequencies and their variations with high time-frequency resolution and veracity.