Title :
Hybrid coding of mixed signals for digital covert audio surveillance
Author :
Mason, Michael ; Sridharan, Sridha ; Chandran, Vinod
Author_Institution :
Sch. of Electr. & Electron. Syst. Eng., Queensland Univ. of Technol., Brisbane, Qld., Australia
Abstract :
An overview of the requirements of digital covert audio acquisition (DCAA) is provided and a scalable hybrid coder tuned for the coding of intelligible speech in a covert environment is proposed. The codec incorporates linear predictive coding (LPC) and an M-band discrete wavelet transform (DWT) to offer effective intelligible speech coding in the presence of multiple signal sources at bit rates between 8 kbps and 32 kbps. The results of informal intelligibility testing and an analysis of the algorithm´s complexity are presented to demonstrate the performance of the proposed coder
Keywords :
computational complexity; discrete wavelet transforms; linear predictive coding; speech codecs; speech coding; speech intelligibility; surveillance; transform coding; 32 kbit/s; 8 kbit/s; DWT; LPC; M-band discrete wavelet transform; algorithm complexity; bit rates; codec; coder performance; covert environment; digital covert audio acquisition; digital covert audio surveillance; hybrid coding; informal intelligibility testing; intelligible speech coding; law enforcement; linear predictive coding; mixed signals; multiple signal sources; scalable hybrid coder; scalable hybrid parametric-transform coder; Australia; Bandwidth; Data compression; Discrete wavelet transforms; Linear predictive coding; Monitoring; Radio access networks; Speech coding; Surveillance; Systems engineering and theory;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE International Conference on
Conference_Location :
Istanbul
Print_ISBN :
0-7803-6293-4
DOI :
10.1109/ICASSP.2000.860194
