Figure 3: Signal composed of two close frequencies components which are successfully separated using the proposed approach while classical EMD fails. (Right column) (solid line) Original curves of the desired sinusoids (tones at f1 = 31Hz and f2 = 30Hz) superimposed to (dashed line) the obtained IMFx,1 and IMFx,2 (8) respectively: separation is correctly achieved using the MD-EMD. (Left column) Original curve of the dominant tone at f1 = 31Hz superimposed to the first IMF obtained using the EMD: separation is not achieved. The sample number N is 220000, the sampling frequency Fs = 44 .1 kHz, f0 = 29 .125 Hz and log10(α)=−0.08. Only a fraction between 6.4 s and 8.9 s is represented from the total signal.