A handout created for PSY 440 (Perception) field trip to a middleschool
Stephen F. Austin State University
What is the Tympanic Membrane and where is it in the hearingprocess?
Commonly known as our eardrum.
Sound moves down the ear canal and reaches the eardrum causing itto move back and forth.
This movement causes three very small bones called the ossicles tomove.
The ossicles moves and transfers sound to the cochlea
Inside the cochlea sound is transferred into neural signals
Why do we need an intact and properly functioning TympanicMembrane?
Because it is a beginning step in the hearing process.
Necessary for being able to hear in the normal hearing range.
Proper hearing is a key part of interaction between people and theenvironment.
Damage to our hearing may affect our perception of speech.
How is hearing loss classified?
Conductive hearing loss occurs when sound is not properlytransmitted to the receptors inside the cochlea.
Sensorineural hearing loss is when there is a problem withchanging sounds we hear into neural signals.
The other way hearing loss happens is when there is a combinationof these two types of hearing loss.
Problems that can damage our Tympanic Membrane:
Cholesteatoma is a growth that can appear behind an intacttympanic membrane or near a perforation of the tympanic membrane. Ifleft untreated a Cholesteatoma can enlarge and reduce movement of thetympanic membrane and the ossicles.
Chronic Otitis Media, also known as a middle ear infection, is acommon cause of hearing loss. Otitis media is a build up of fluidbehind the tympanic membrane that occurs more than three times in sixmonths or four times in one year. The infection is usually associatedwith cold, allergies and malfunctioning Eustachian tubes. The fluidbuild up can sometimes cause the tympanic membrane to burst.
Tympanosclerosis is a build up of calcium deposits on the tympanicmembrane, which causes it to become harder and reduces movement ofthe hearing system.
Trauma to the Tympanic Membrane can be caused by water accidents,barotraumas, explosions, temporal bone fractures and penetrationtrauma. Any one of these can cause the tympanic membrane to becomeperforated. Perforations reduce the surface area available fortransmission of sound to the ossicles, and invite chronic otitismedia to occur at a high rate. About 90% will heal on their ownwithin three months of appearance. A perforated tympanic membrane canalso cause the other problems listed above to occur.
Ways to prevent infection of and correct perforations of thetympanic membrane:
Ventilation Tubes are surgically implanted into the tympanicmembrane to allow fluid to drain from the middle ear. The tubes arecommonly implanted in children with malfunctioning Eustachian tubes.The tubes will be pushed out of the tympanic membrane as itregenerates.
A Non-surgical closure of the tympanic membrane is a process thattakes several steps and can be performed in a doctor's office. It isonly meant for simple perforations. Step 1 is the area around theperforation is cauterized by a solution of acid. The acid breaks downthe build-up of material that is preventing the perforation to heal.In Step 2 antiseptic powder is applied and the perforation is thencovered with some sterile cotton that has enthymol solution in it.The cotton acts as a splint and allows the perforation to close. InStep 3 the patient is sent home and instructed to put enthymol eardrops in the affected ear twice a day and return in ten days for afollow up. The treatment is usually successful in one to threetreatments. The procedure works with people of any age and aperforation of any size. The only complication is when theperforation is located at the front of the tympanic membrane.
Myringoplasty is a very common ear surgery. It refers to therepair of a damaged tympanic membrane.
Tympanoplasty includes the repair of the tympanic membrane, butalso includes the repair of the hearing mechanism and prevention ofmiddle ear disease and infection.
The Underlay Procedure is a commonly used procedure to surgicallyclose a perforation of the tympanic membrane. The procedure involvesan incision made behind the patient's ear so it can be moved out ofthe way. The tympanic membrane is cut so that a skin graft can beplaced under the perforation. The procedure is 90% successful andshows about a 59% improvement in hearing. A problem with theprocedure is when the perforation is located in the front of thetympanic membrane.