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Accelerometer close-up

A very close view of an accelerometer chip

While researching the possibilities for using accelerometers for recording sound (struck out on Google, anyone know how this works?) I found this image of an extreme close-up of an accelerometer chip. The chip itself is only 5mm square.

Here’s a wider shot (click on image for much larger version):

Via: Sensor Mag

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Our ears make sounds

The cilia of the inner ear - downloaded long ago, no source
The cilia of the inner ear - downloaded long ago, no source

According to this interesting article in New Scientist, our ears make sounds.  Called otoacoustic emissions or OAE’s, the tiny hairs in the ears (above) make very quiet sounds that are unique to an individual.

That’s because “hearing is an active process – the ear actually puts energy into the incoming sound waves to replace energy lost as sound is absorbed by the ear’s structure”, says Stephen Beeby, an engineer at the University of Southampton, UK, who is leading the research. “This process helps us hear things we otherwise would not, but as a result some of the energy added by the hair cells escapes as OAEs.”

Jacob Kirkegaard recording "Labyrithitis"

These sounds are between 0-5kHz and are thought to maybe be a kind of biometric password to be used over the phone.  A quick search found no recordings of OAE’s but did turn up the work “Labyrinthitis” by Jacob Kirkegaard.  The work is complicated, but Kirkegaard essentially recorded the frequencies his ear produced, synthesized and arranged a composition with them, and output them in a large performance/installation at the Medical Museion in Copenhagen.  The description of this work goes into more detail of how the piece was constructed and well worth the read.  An excerpt of a recording is below: