Device mimics fly's super hearing
Engineers at the University of Texas have designed a device modeled after the extremely sophisticated hearing of a fly and one day could allow humans to hear only the sounds and conversations they want to hear.
For the research, published in Applied Physics Letters, the scientists focused on the technological potential of mimicking the hearing of the Ormea ochracea fly, which is capable of locating male field crickets from their chirps, and then lays live larvae on and around them. The flies are able to locate the crickets from their sound within an angle of two degrees. Humans locate sound by using the distance between both ears. The sound hits the ears at different times, which helps the brain locate the source. Insect bodies are generally too small to do this, but certain insects, such as the fly, use a different type of mechanism. It amplifies the time difference using a teeter-totter method, allowing the insect to sense the 4-millimeter gap between the sound entering one ear and the other.
Using the fly’s hearing as a model, the researchers made a tiny pressure-sensing device out of silicon. They created a flexible beam using piezoelectric materials that allowed them to use the flexing and rotation of the beam as a way to measure sound pressure and pressure gradient at the same time. These materials convert the mechanical pressure into electrical signals, which allows the device to work with very little power. That distinguishes this device from others that have been designed.
Researchers hope this can become a new and more sophisticated type of hearing aid.