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Lecture 8
Neuromorphic Hearing
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Outline
• The ear and the cochlea
• Silicon Cochlea
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Ear and Cochlea Cross Section
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Retina Cells
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Hair Cells
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Outline
• The ear and the cochlea
• Silicon Cochlea
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Modeling of the filtering operation
• The cochlea can be modeled as several 2order filters in parallel.
• Each filter is creater cascoding several 2-order
low pass filters.
• More stability and gain is achieved.
• The spatial dependence of the cut-off
frequency is modeled with distributed
resistors.
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Resonant low pass filter with transconductance amplifiers (I)
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Resonant low pass filter with transconductance amplifiers (II)
• Second order transfer function:
• Generic second order transfer function:
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Second order filters in parallel
Filters are tuned with exponentially increasing time constants
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Second order filters in cascade
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A SILICON COCHLEA
Richard F. Lyon and Carver Mead, ”An Analog Electronic Cochlea”, IEEE
Trans. On Acustics, Speech and Signal Processing, Vol. 36, NO. 7, July
1998.
1000 cascode filters were employed. A real emulation should
use 3000.
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