ISSN:
1573-1979
Keywords:
active cochlea
;
analogue VLSI
;
automatic gain control
;
biological modelling
;
quality factor modulation
;
pseudoresonance
;
second-order filter cascade
;
silicon cochlea
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
Notes:
Abstract A model of an active cochlea featuring a frequency selectivegain adaptation is proposed. The model is developed for analogueVLSI implementation and is based on the original “analog electroniccochlea” proposed by Lyon and Mead (1988) which consists ofa second-order lowpass filter cascade. At any position alongthe cochlea, the gain is locally controlled by the output levelat this position through the quality factor of the second-orderlowpass filter which best participates to this local gain. Inorder to achieve a 40dB compression with a limited local qualityfactor, the pseudoresonance of the cascade is used. A carefulanalysis of the functional model, supported by realistic computersimulations, shows the validity of the model by comparison withits biological counterpart. All the building blocks for an analogueVLSI implementation are proposed, taking into account the majortechnological limitations of a standard CMOS process.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008234622348
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