Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Pitch- and Formant-Based Order Adaptation of the Fractional Fourier Transform and Its Application to Speech Recognition | Hindawi Publishing Corporation EURASIP Journal on Audio Speech and Music Processing Volume 2009 Article ID 304579 14 pages doi 2009 304579 Research Article Pitch- and Formant-Based Order Adaptation of the Fractional Fourier Transform and Its Application to Speech Recognition Hui Yin 1 2 Climent Nadeu 1 and Volker Hohmann1 3 1TALP Research Center Universitat Polit ecnica de Catalunya 08034 Barcelona Spain 2 Department of Electronic Engineering Beijing Institute of Technology Beijing 100081 China 3 Medizinische Physik Universitat Oldenburg 26111 Oldenburg Germany Correspondence should be addressed to Hui Yin hchhuihui@ Received 27 March 2009 Revised 6 August 2009 Accepted 21 November 2009 Recommended by Mark Clements Fractional Fourier transform FrFT has been proposed to improve the time-frequency resolution in signal analysis and processing. However selecting the FrFT transform order for the proper analysis of multicomponent signals like speech is still debated. In this work we investigated several order adaptation methods. Firstly FFT- and FrFT- based spectrograms of an artificially-generated vowel are compared to demonstrate the methods. Secondly an acoustic feature set combining MFCC and FrFT is proposed and the transform orders for the FrFT are adaptively set according to various methods based on pitch and formants. A tonal vowel discrimination test is designed to compare the performance of these methods using the feature set. The results show that the FrFT-MFCC yields a better discriminability of tones and also of vowels especially by using multitransform-order methods. Thirdly speech recognition experiments were conducted on the clean intervocalic English consonants provided by the Consonant Challenge. Experimental results show that the proposed features with different order adaptation methods can obtain slightly higher recognition rates compared to the reference MFCC-based recognizer. Copyright 2009 Hui Yin et al. This is an open access .