Fig. 1. Speech spectrograms and energy peak point distribution of Chinese phonetic syllables. (a) Original speech spectrogram; (b) speech envelope spectrogram; (c) energy peak point distribution

Fig. 2. Syllable matching algorithm steps

Fig. 3. Extraction of spectral peak point feature

Fig. 4. Gray-scale spectrogram of speech signal

Fig. 5. Envelope spectrogram of speech signal

Fig. 6. Energy point after thresholding

Fig. 7. Envelope spectrograms. (a) Envelope spectrogram of commonly used Chinese character pronunciation “de”; (b) envelope spectrogram after discarding partial information blow 300 Hz

Fig. 8. Distribution of energy maximum points using different division methods in frequency bands. (a) Frequency band is equally spaced; (b) logarithmic division of frequency bands

Fig. 9. Illustration of two maximum feature points in each signal frame