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 Wideband Speech Recovery Using Psychoacoustic Criteria | Hindawi Publishing Corporation EURASIP Journal on Audio Speech and Music Processing Volume 2007 Article ID 16816 18 pages doi 2007 16816 Research Article Wideband Speech Recovery Using Psychoacoustic Criteria Visar Berisha and Andreas Spanias Department of Electrical Engineering Arizona State University Tempe AZ 85287 USA Received 1 December 2006 Revised 7 March 2007 Accepted 29 June 2007 Recommended by Stephen Voran Many modern speech bandwidth extension techniques predict the high-frequency band based on features extracted from the lower band. While this method works for certain types of speech problems arise when the correlation between the low and the high bands is not sufficient for adequate prediction. These situations require that additional high-band information is sent to the decoder. This overhead information however can be cleverly quantized using human auditory system models. In this paper we propose a novel speech compression method that relies on bandwidth extension. The novelty ofthe technique lies in an elaborate perceptual model that determines a quantization scheme for wideband recovery and synthesis. Furthermore a source filter bandwidth extension algorithm based on spectral spline fitting is proposed. Results reveal that the proposed system improves the quality of narrowband speech while performing at a lower bitrate. When compared to other wideband speech coding schemes the proposed algorithms provide comparable speech quality at a lower bitrate. Copyright 2007 V. Berisha and A. Spanias. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The public switched telephony network PSTN and most of today s cellular networks use speech coders operating with limited bandwidth kHz which in turn places a limit on the naturalness and intelligibility of speech 1 . This
