Functions In The Ear

A basic understanding of how the ear functions will help you better understand hearing tests and audiograms.  The different functions of the ear have an impact on hearing levels and listening ability.

The ear is divided into three parts - the outer ear, middle ear, and inner ear.

Sound waves travel through the ear canal and to the eardrum.  The sound waves cause the eardrum to vibrate and pass through the middle ear bones, which creates movement in the fluid of the inner ear.  This snail-shaped structure, called the cochlear, contains thousands of hair cells.  The movement of the hair cells sends electric signals from the inner ear up the auditory nerve to the brain.

The brain then interprets these electrical signals as sound. Sound is described in decibels and frequencies.

• Decibels (dB) are how quiet or loud a sound is.
• Frequencies (measured in Hz) are how low or high in pitch sound is.

Sound is not the same for everyone.

Because of the unique nature of each person's physiology and brain structure, sound is not the same for everyone. It can explain why a person likes the song of a bird and another person may hate it. Each child who is deaf and hard of hearing has unique hearing levels and listening abilities. Refer to the child's audiogram and speech banana audiogram when discussing hearing levels.