The Inner Ear

The Inner Ear (Cochlea) is where transduction takes place.

Diagram Figure A-17 from the text, page 396 -- the Inner Ear or Cochlea (colors added).



The Cochlea is a double layered tube filled with fluid.

The floor of the Cochlea has the Basilar Membrane on which are four rows of hair cells.

The celia on some hair-cells on the Basilar Membrane are bent by each sound wave that enters the fluid.

Diagram Figure A-18 from the text, page 397 -- a cross section of the Cochlea (colors added).



The hair-cells along the Basilar membrane respond selectively to specific frequencies.

A hair-cell and the nerve connected to it is called a Basic Sensory Unit.

A sensory neural loss usually begins in the higher frequencies and works it way down.

An Audiogram is a chart of hearing ability.

An audiogram showing a significant loss above 4000 Hz.



An audiogram showing a significant loss above 2000 Hz.



An audiogram showing a significant loss above 1000 Hz.



An audiogram showing a significant loss above 500 Hz.



Amplification will not always improve speech discrimination affected by a sensory neural loss.

It is important to identify a hearing loss as early as possible and to develop a program of auditory training.

A sensory neural loss is not reversible.

The Cochlear Implant is an artificial cochlea that has considerable promise for adults and children.