O'Reilly logo

Event-Based Neuromorphic Systems by Rodney Douglas, Adrian Whatley, Giacomo Indiveri, Tobi Delbruck, Shih-Chii Liu

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

4

Silicon Cochleas

images

While the previous chapter was about neuromorphic silicon retinas, this one is on silicon cochleas. The cochlea is biology’s sound sensor – it turns vibrations in the air into a neural signal. This chapter briefly explains the operation of the various components of the biological cochlea and introduces circuits that can simulate these components. Silicon cochlea designs typically divide the biological cochlea into several sections that are equally spaced along its length. Each section is then modeled by an electronic circuit. Silicon cochlea designs may be classified as 1D or 2D, depending on the coupling between these sections. Circuits for both variants are presented. They may also be classified as active or passive, depending on whether the quality factor of each cochlear section changes as a function of the output signal of the section or not. Details for both implementations are presented. A tree diagram at the end of the chapter illustrates the progression of silicon cochlea modeling.

4.1  Introduction

The biological cochlea is a bony, fluid-filled, spiral structure that forms the majority of the inner ear. It performs the transduction between the pressure signal representing the acoustic input and the neural signals that carry information to the brain. Figure 4.1 shows the location of the cochlea relative to other key features in the human ear.

The cochlea ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required