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Sound
2. HEARING AND THE EAR
Sound itself is both a physical and psychological phenomenon. Waves of sound caused by a vibrating object are basically minute changes in air pressure. The waves have no significance, no message until they reach the ear. The hearing process is a chain of events in which the waves are conducted through the ear and translated into nerve impulses for interpretation by the brain, The hearer instantly distinguishes the meaning of those signals. 'The Three Compartments of the Ear
The ear is divided into three sections:
The
The
The
external
middle
internal
The outer ear consists of the auricle which acts as a sound-gathering funnel and the ear-canal which leads to the cardrum.
The middle ear begins at the tympanic membrane or cardrum. The tympanic cavity is air-filled and the internal air pressure is maintained at the same level as the external atmosphere. It contains the ossicles, three tiny bones named for their distinctive shapes: the malleus (meaning hammer), incus (anvil) and stapes (stirrup). The three ossicles stretch from the eardrum to the oval window, an opening in a very thin bony wall which seperates the middle and the internal ear. The three bones are linked together but not rigidly, so that the vibrations of the eardrum are magnified in force by the jiggling motion of the ossicles. The amplified vibrations of sound pressure are transmitted to the fluid-filled inner ear via the oval window.
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ear,
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ear.
and
The internal ear contains the organ of hearing and is described in two parts:
The bony labyrinth.
The membranous labyrinth.
The membranous labyrinth has the same shape as the bony labyrinth and fits into it like a tube within a tube.
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