Title :
Log-domain circuits for auditory signal processing
Author :
Edwards, R. Timothy ; Cauwenberghs, Gert
Author_Institution :
Appl. Phys. Lab., Johns Hopkins Univ., Laurel, MD, USA
Abstract :
The theory and practice of log-domain filter design has reached the point where it is possible to incorporate log-domain filter structures into large current-mode VLSI systems. We report on interface circuits used to implement a current-mode frontend filterbank and feature extractor for acoustic pattern recognition. These circuits maintain a log-domain structure, acting on the unexpanded filter output to execute such functions as peak-to-peak voltage measurement, full-wave rectification, smoothing, and normalization. A fabricated VLSI sixteen-channel filterbank feature extractor exhibits 40 dB resolution for short-term energy envelope measurements of class A log-domain second-order bandpass filter outputs
Keywords :
VLSI; acoustic signal processing; active filters; analogue integrated circuits; analogue processing circuits; audio signal processing; band-pass filters; current-mode circuits; feature extraction; pattern recognition; rectification; smoothing methods; acoustic pattern recognition; auditory signal processing; class-A operation; current-mode VLSI systems; current-mode frontend filterbank; feature extractor; full-wave rectification; interface circuits; log-domain circuits; log-domain filter; log-domain filter design; normalization; peak-to-peak voltage measurement; second-order bandpass filter outputs; smoothing; Acoustic signal processing; Band pass filters; Circuits; Feature extraction; Filter bank; Filtering theory; Pattern recognition; Signal processing; Very large scale integration; Voltage measurement;
Conference_Titel :
Circuits and Systems, 1999. 42nd Midwest Symposium on
Conference_Location :
Las Cruces, NM
Print_ISBN :
0-7803-5491-5
DOI :
10.1109/MWSCAS.1999.867796
