The application of Hilbert-Huang transform in speech coding algorithm for cochlear implants / 中国医疗器械杂志

ABSTRACT

To enhance speech recognition in realistic listening environment, as well as tonal language and music perception, a new speech coding strategy based on Hilbert Huang transform was presented. Instantaneous frequency and instantaneous amplitude which reflect speech contents, speech rhythms and tones are derived from original speech signal through empirical mode decomposition and the Hilbert transform to synthesize stimulating pulses. The presented new speech coding algorithm, continuous interleaved sampling, and frequency amplitude modulation encoding strategies were simulated by Matlab and synthesized signals of 50 Mandarin speech test materials are correlation analyzed between original signals. Compared to other two strategies, the presented new strategy obtains the highest correlation coefficient between synthesized signal and that of original speech, which indicates it could keep more information of the original speech signal than other two strategies.