How we hear sound

Sound waves enter the outer ear (pinna) and set the eardrum vibrating. This vibration is carried through the ossicles causing the innermost one (stapes) to vibrate against the oral window, thus amplifying the sound waves. The vibration of the stape causes the fluid in the cochlea to vibrate. This vibration produces impulses (electrical energy) which are transmitted to the brain through the auditory nerves. The brain then interprets the impulses as sound with the correct pitch.

The ear therefore helps vertebrates, especially those on land, to monitor their environments, to detect possible sources of danger and escape where necessary.

It is important to mention that the maximum sound intensity, safe for hearing is 85db. When a person is exposed to sound intensity above 85db, for a long period of time, deafness may be the result. Excessive noise is termed as noise pollution.

Post a Comment

0 Comments