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 Analysis of Acoustic Features in Speakers with Cognitive Disorders and Speech Impairments | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 159234 11 pages doi 2009 159234 Research Article Analysis of Acoustic Features in Speakers with Cognitive Disorders and Speech Impairments Oscar Saz 1 Javier Simon 2 Rodríguez 1 Eduardo Lleida 1 and Carlos Vaquero1 1 Communications Technology Group GTC Aragon Institute for Engineering Research I3A University of Zaragoza 50018 Zaragoza Spain 2Department of General and Hispanic Linguistics University of Zaragoza 50009 Zaragoza Spain Correspondence should be addressed to Oscar Saz oskarsaz@ Received 31 October 2008 Revised 11 February 2009 Accepted 8 April 2009 Recommended by Juan I. Godino-Llorente This work presents the results in the analysis of the acoustic features formants and the three suprasegmental features tone intensity and duration of the vowel production in a group of 14 young speakers suffering different kinds of speech impairments due to physical and cognitive disorders. A corpus with unimpaired children s speech is used to determine the reference values for these features in speakers without any kind of speech impairment within the same domain of the impaired speakers this is 57 isolated words. The signal processing to extract the formant and pitch values is based on a Linear Prediction Coefficients LPCs analysis of the segments considered as vowels in a Hidden Markov Model HMM based Viterbi forced alignment. Intensity and duration are also based in the outcome of the automated segmentation. As main conclusion of the work it is shown that intelligibility of the vowel production is lowered in impaired speakers even when the vowel is perceived as correct by human labelers. The decrease in intelligibility is due to a 30 of increase in confusability in the formants map a reduction of 50 in the discriminative power in energy between stressed and unstressed vowels and to a 50 increase of the standard deviation in the length of .