June 02, 2009 Today ’ s Agenda – Warm up – Video 06/02: Min day 06/03: 06/04: CE Due 06/05: Return Books to Library 06/08: Unit Test Warm- up question: How does a person become cross eyed? What can be done to correct this?

June 03, 2009 Today ’ s Agenda – Warm up – Notes on Ear structure 06/04: CE Due 06/05: Return Books to Library 06/08: Unit Test 06/09: 1 & 2 Finals 06/10: 3 & 4 Finals 06/11: 5 & 6 Finals Warm- up questions: What is sound? What is the danger of using a Q-tip to clean your ear? What is another name for the Tympanum? What is the function of the tympanum?

June 04, 2009 Today ’ s Agenda – Warm up – Video – Notes on Hearing disorders 06/05: Return Books to Library NO one is allowed to stop at lockers! 06/08: Unit Test 06/09: 1 & 2 Finals & CE Due 06/10: 3 & 4 Finals & CE Due 06/11: 5 & 6 Finals & CE Due TURN IN YOUR CE ON THE FRONT TABLE Warm- up questions: What are the components of the middle ear? Use the scientific terms and list them in the order that vibrations would be passed through them. What would happen if you were born with a stapes that is not formed correctly?

Warm up: What is the scientific term for being cross-eyed? What causes it? What can be done to treat it? 24 Lab Final Draft 25 Min Day 2627 Min Day CE 28 Last day for Late work 31 NO SCHOOL 1 Min Day 2 Min Day 3 CE Grad Night 4 Sub Test 78 Finals 1 & 2 CE 9 Finals Graduation 3 & 4 CE 10 Finals 5 & 6 CE

The Mammalian Ear

Sound Vibrations in the air

The Ear The human ear has two sensory functions: – hearing – balance

The Ear Hearing – Ears can distinguish both the pitch and loudness of those vibrations.

3 parts to the ear Outer Ear Middle Ear Inner Ear

Outer Ear Pinna Auditory Canal

The Ear Pinna is the external part that we think of as “the ear.” It helps to collect sound waves. Vibrations enter through the auditory canal. Auditory canal

The middle ear Consists: – Tympanum – Malleus – Incus – Stapes – Eustachian tube

The Ear The vibrations cause the tympanum, or eardrum, to vibrate. Tympanum

The Ear The vibrations are picked up by the hammer, transferred to the anvil, and then the stirrup. Hammer (malleus) Anvil (Incus) Stirrup (Stapes) Pinna Eustachian tube

The Ear Eustachian Tube – runs from middle ear to the pharynx. It allows small amounts of air in to equalize the pressure between the middle ear and the atmosphere. Hammer (malleus) Anvil (Incus) Stirrup (Stapes) Pinna Eustachian tube

When the Eustachian tube functions normally, every single time you swallow, yawn, blow your nose, etc, your ear "pops". This popping is when the Eustachian tube opens transiently allowing air to pass in. When you have a cold the “clogged” feeling is mucus build up in the tube. Blowing your nose to hard can cause bacteria to be forced up into the Eustachian tube and can lead to infection.

Inner Ear Consists of: – Cochlea – Oval window – Round window – Semi-circular Canals

The Ear The stirrup transmits the vibrations to the oval window. Oval window Stirrup (Stapes) Round Window

The Ear The round window expands out to accommodate pressure. Oval window Stirrup (Stapes) Round Window

The Ear Vibrations of the oval window create pressure waves in the fluid-filled cochlea of the inner ear. Cochlea

The Ear The cochlea is lined with tiny hair cells that are pushed back and forth by these pressure waves. In response to the waves, the hair cells produce nerve impulses that are sent to the brain through the cochlear nerve.

The Ear – Balance Your ears help you to maintain your balance, or equilibrium.

The Ear Within the inner ear, just above the cochlea are three semicircular canals. Semicircular canals

The Ear The canals are filled with fluid and lined with hair cells. As the head changes position, fluid in the canals changes position, causing the hair on the hair cells to bend. This sends impulses to the brain that enable it to determine body motion and position.

Hearing Impairments Conductive Hearing Loss Nerve Deafness Central Hearing loss

Conductive Hear Loss Sound is not conducted properly through the outer ear, middle ear, or both. Generally a mild to moderate impairment, because sound can still be detected by the inner ear. Quality of hearing (speech discrimination) is good, as long as the sound is amplified loud enough to be easily heard. Causes include: – Ear canal obstruction – Middle ear abnormalities: Tympanic membrane Ossicles (Malleus, Stapes, Incus)

Nerve Deafness Auditory nerve, which goes from the inner ear to the brain, fails to carry the sound information to the brain. Neural hearing loss can cause a loss of loudness or a loss of clarity in sounds. This is a problem getting the signal to the brain.

Central Hearing loss Perceptive: In this type of deafness, the sound waves can reach the inner ear but there is an impairment in the nerves leading to the brain, due to which sound cannot be sensed.

Central hearing loss The brain processing of the stimulus is not functioning properly. This is a problem with the brain interpreting the signals.

Causes of Hearing Loss/Deafness Heredity Ear infections Otosclerosis

Causes of Hearing Loss/Deafness Heredity. Some people are born deaf. Usually the cause is unknown.

Causes of Hearing Loss/Deafness Ear infections Increase fluid = increase pressure = eardrum less flexible = hearing loss cause fluid to build up inside the ear. Pressure builds up inside the ear, the eardrum is less flexible. Some hearing may be lost during the infection; it may or may not return when the infection is healed.

Causes of Hearing Loss/Deafness Otosclerosis: hereditary disease in which portions of the middle ear or inner ear develop growths like bony sponges

Causes of Hearing Loss/Deafness Loud Noises: repeated or long-term exposure to loud noises. This is why heavy equipment operators, firefighters, factory workers, and especially rock musicians suffer hearing losses after years of their work. Usually a single incident of exposure to loud noises will not cause deafness, but a repeated exposure to loud noises over a period of time will often cause moderate to severe hearing loss.

Hearing Aids Amplify sound waves or makes bones move 3 Types: – External: inserted into the auditory canal – Implanted: attached to one of the bones of the middle ear. Moves these bones directly. – Bone-anchored hearing aid: attaches to the bone behind the ear. The device transmits sound vibrations directly to the inner ear through the skull, bypassing the middle ear.

Cochlear Implant – do not write…LISTEN A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts: A microphone, which picks up sound from the environment. A speech processor, which selects and arranges sounds picked up by the microphone. A transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses. An electrode array, which is a group of electrodes that collects the impulses from the stimulator and sends them to different regions of the auditory nerve. An implant does not restore normal hearing. Instead, it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech.