The logarithmic energy output of the filters during the pronunciation of words, sentences are presented in 10 ms steps. Light colours present the high energy level, the dark one the low energy levels. Colours change in 6dB s steps. Phonemes with noise components are presented by yellow and read colours, vowels are presented by white and blue ones. In the case of the best fitting we compare the two spectrograms.
White rectangles are drown where the difference is negative, and green when difference is positive.
On the computer screen the energy levels of the spectral components are presented. The distribution line of each correctly pronounced sound is very typical. It gives possibilities for an automatic feedback. The pronunciation is not acceptable, when the measured data will be outside the allowed distribution line, when spectral distance is bigger that a threshold. Here we calculated the distance of the spectrum components of an actual pronunciation from the averaged good examples.