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Phoenix666 [soylentnews.org] writes:

Last week, at the IEEE International Solid-State Circuits Conference [isscc.org] in San Francisco, another group showed how this approach can also work for hearing. Shi-Chii Liu [ini.uzh.ch], who co-leads the Zurich institute, described a silicon cochlea that uses just 55 microwatts of power (three orders of magnitude less than previous versions of the system) to detect sound in a humanlike way.

The neuromorphic auditory system uses two “ears,” with each one capable of being moved independently of the other. The difference in timing between sound waves reaching the two ears makes it possible to locate the origin of a sound, says Liu. Each silicon ear has 64 channels [ieee.org], which each responds to a different frequency band, from low pitches to high. These channels mimic the cells in the human cochlea, which also responds to different frequencies (about a thousand in the real thing).

Liu connects the silicon cochlea to her laptop and shows what it’s recording with a graph of frequency over time. When we’re quiet, there’s no activity. When one of us speaks into the microphone, there are spikes around the 100-to-200-hertz range. The other channels, ranging from 20 Hz to 20 kilohertz, are not recording.

Original Submission