hearing
On the performance of the ear
Our sense organs are the interface between brain and environment.
The high evolutionary pressure on the optimization of the hearing performance has made the ear in many respects to a high performance sensory system. The sensitivity is such that extremely small amounts of energy (in the form of sound pressure) are detected. The detection limit of the human acoustic system is comparable to the sensitivity of typical high-tech products, such as micro-wave receivers, which are built into satellite dishes. If the ear would be only slightly more sensitive, we could literally hear the noise of atoms that impinge on the eardrum due to the thermal motion of the air.
Additionally we are able to locate a sound source without the help of other senses. Dirctional hearing of mammals is well developed and allows, for example, the prey to escape in the safe direction.
The analysis of complex sounds (speech, animal noises, etc) requires the ability to differentiate tones of different frequencies. The frequency analysis is therefore another important feature of the hearing organs.
In the lab course the absolute threshold of hearing will be determined with respect to the frequency. Various factors affecting directional hearing are investigated and experiments on spectrum analysis will be carried out.
Duration: 0.5 - 1 days
Max participants: 18
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