HEARING

WHAT IS HEARING?

• Hearing, auditory perception, or audition is the ability to perceive sound by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear.

TRIVIAS

• Your ear bones are the smallest bones in our body.

• The ear continues to hear sounds, even while you sleep.

• Sitting in front of the speakers at a rock concert can expose you to 120 decibels, which will begin to damage hearing in only 7 ½ minutes.

BASIC PARTS & FUNCTIONS OF EAR

• PINNA-is the visible part of the ear outside of the head

• EAR CANAL-The ear canal has hairs near the outer end; these hairs are used to keep foreign objects like dust.

• EAR DRUM- Its function is to transmit sound from the air to the ossicles inside the middle ear, and then to the oval window in the fluid-filled cochlea.

• INCUS - The Incus serves as a connection that receives sound waves, captured by the malleus, transmits that sound to the stapes.

• MALLEUS- The malleus is one of three ossicles in the middle ear which transmit sound from the tympanic membrane (ear drum) to the inner ear. The malleus receives vibrations from the tympanic membrane and transmits this to the incus.

• STAPES - Situated between the incus and the inner ear, the stapes transmits sound vibrations from the incus to the oval window.

• ROUND WINDOW – The function of the round window, a membrane-covered opening between the middle ear and the cochlea, is to allow for pressure changes between the middle ear and the cochlea.

• SEMICIRCULAR CANALS - Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance. When your head moves around, the liquid inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.• VESTIBULE - The vestibule is the central part

of the osseous labyrinth, and is situated medial to the tympanic cavity, behind the cochlea, and in front of the semicircular canals.

• VESTIBULAR NERVE – The primary role of the vestibular nerve is to transform vestibular information (related to balance) into an egocentric frame of reference based on the position of the head in relation to the body.

• COCHLEAR NEREVE – Is a nerve in the head that caries signals from the cochlea of the inner ear of the brain.

• COCHLEA – The cochlea is filled with a watery liquid, the perilymph, which moves in response to the vibrations coming from the middle ear via the oval window.

• TYMPANIC CAVITY – The middle ear or tympanic cavity is an irregular, laterally compressed space within the temporal bone. It is filled with air, which is conveyed to it from the nasal part of the pharynx through the auditory tube.

• EUSTACHIAN CAVITY - The primary function of the Eustachian tube is to ventilate the middle ear space, ensuring that its pressure remains at near normal environmental air pressure. The secondary function of the Eustachian tube is to drain any accumulated secretions, infection, or debris from the middle ear space.

HEARING SYSTEM

• Sound is transformed into mechanical vibration at the ear drum. The eardrum is attached to a chain of three hearing bones that act as a lever enhancing sounds while transferring the signal through the middle ear to the inner ear.

COMMON DISEASES

• Earache: Pain in the ear can have many causes. Some of these are serious, some are not serious.

• Otitis media (middle ear inflammation): Inflammation or infection of the middle ear (behind the eardrum). Usually, this is caused by an infection.

• Swimmer’s ear (Otitis externa): Inflammation or infection of the outer ear (pinna and ear canal). Sudden cases are usually infections; chronic otitis is often a skin condition (dermatitis).

• Meniere’s disease: A condition in which the inner ear on one side malfunctions. Vertigo, tinnitus, hearing loss, and pain are common symptoms.

• Tinnitus: Ringing in one or both ears. Usually this is due to damage from noise exposure, or from aging.

• Cerumen (ear wax) impaction: Ear wax may block the ear canal and adhere to the eardrum. The eardrum’s reduced vibrations impair hearing.

• Ruptured eardrum: Very loud noises, sudden changes in air pressure, infection, or foreign objects can tear the eardrum. The small hole usually heals within a few weeks.

• Cholesteatoma: This is a benign condition. It is the buildup of fibrous tissue within the middle ear and surrounding bones. Often there is a foul smelling discharge associated with hearing loss.

• HEREDITY• DISEASES SUCH AS EAR INFECTION

AND MENINGITIS• TRAUMA• CERTAIN MEDICINES• LONG-TERM EXPOSURE TO LOUD

NOISE• AGING

SOME POSSIBILITIES OF CAUSING HEARING LOSS

WAYS TO PREVENT HEARING LOSS

• AVOID EXPOSING TO LOUD NOISE• DON’T USE MEDICINES WITH SIDE

EFFECTS• DON’T CLEAN YOUR EARS EVERYDAY• AVOID USING IMPROPER TOOLS FOR

EAR CLEANING• AVOID INJURIES