Published by Australian Academy of Science
Activity 2 | Cochlear implants – wiring for sound

The ear and hearing

1. As with many organs in the body, the structure of the ear is related to its function.
   • Draw up a two-column table. List the parts of the ears in the left-hand column and in the right-hand column list the functions of each part.

2. Sound is produced by a vibrating object that generates pressure waves.
   • Outline how a stimulus of sound is sent to the brain.

3. What structure(s) of the ear would you expect to be most vulnerable to damage by the 'noise pollution' that we are exposed to in today's environment.

4. Explain why a temporary hearing loss is produced when the external ear is blocked by ear wax.

5. Explain why a loud explosion or a blow on the side of the head that ruptures the eardrum causes a loss of hearing until the ear drum has healed.

6. Explain why having two ears enables us to more easily locate where a sound comes from.

7. Sounds must reach a certain intensity (volume) before they can be detected by the human ear.
   • Use the ticking of a watch or clock as the sound stimulus and the distance of the watch from the ear as the measure of intensity. Compare the hearing distance when the watch is moved away from the subject with the hearing distance when the watch is moved toward the subject. (Blindfold the subject and carry out the test in a quiet room.)