Ormia
Head-Fier
- Joined
- Oct 28, 2015
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Thanks for the info!
My avatar picture is of the acoustic parasitoid fly Ormia ochracea, a parasitoid of singing field crickets. The fly is tethered to a stick and held stationary ontop of a spherical treadmill (ping pong ball floating on an air stream). When she walks, the ball rotates and the motion is transduced with a modified optical mouse sensor. She has a pair of eardrums that she wears on her chest that allows her to find the location of a singing cricket to the accuracy of 2 degrees azimuth. In other words, put a speaker directly in front of the fly, the fly walks straight to track the speaker location. Move that speaker just 2 degrees to the left, 75% of the time, the fly will make a corresponding behavioural shift to track the change in speaker location. This level of directional acuity is on par with human hearing under the best acoustic conditions using headphones (must mention headphones here just to pretend that I'm still on topic) and simulated interaural time differences..
Interaural time differences for a sound at 2 degrees off of straight ahead is about 50 nanoseconds. Ormia has specialized eardrum mechanics that translates this minute time difference into something amenable (on the order of microseconds) for the neural processing of sound direction... .now isn't this really cool?