How we hear

 The ear consists of 4 parts which work together to help us detect and interpret sound:

The Outer Ear - This part of the ear functions to collect sound and aid in sound localization. If the outer ear is damaged or the ear canal is occluded with cerumen (ear wax), the result is a conductive hearing loss.

Parts of the Outer Ear:

1. pinna: the visible protrusion at the sides of the head
2. external auditory canal (ear canal): opening which funnels sound toward the eardrum. It contains cerumen, a wax-like substance, which helps to moisten the skin of the canal to protect the inner portion of the canal.

The Middle Ear - The function of the middle ear is to transmit sounds from the outer to inner ear. When damage occurs to the middle ear, the resulting hearing loss is termed a conductive hearing loss.

Parts of the Middle Ear:

1. tympanic membrane (eardrum): serves as a seal between the outer and middle ear. Acts as a receiver of mechanical sound energy. sound waves from the ear canal hit the eardrum and set the middle ear bones into vibration.
2. ossicles (middle ear bones): the 3 bones - malleus, incus and stapes, which work together to transmit vibration from the eardrum to the oval window of the inner ear.
3. eustachian tube: it is an opening connecting the middle ear space to the nasopharynx. It functions to equalize middle ear pressure.

The Inner Ear - The function of the inner ear is to convert sound waves from the middle ear (vibration) to electrical energy, which is then transmitted along the acoustic nerve. The inner ear also houses the vestibular system, which is responsible for balance and orientation in space. Damage to the inner ear results in sensorineural hearing loss.

Parts of the Inner Ear

1. cochlea: shaped like a snail shell and contains the essential organs for hearing
2. semicircular canals: essential for balance and orientation in space.

Auditory (Acoustic) Nerve - Transmits the electrical auditory signal from the cochlea to the brain (temporal cortex) where the signal is interpreted. Damage to the auditory nerve is termed sensorineural, retrocochlear, auditory neuropathy, or central.

The Ear

 

Hearing loss can interfere with the quality of life you've hoped for. It can restrict your ability to interact with others, prevent you from hearing important information, cause misunderstandings, heighten stress, cause unnecessary fatigue and filter out the subtle sounds of nature. Don't let poor hearing make you miss out on the many good and vital messages of life.