1. Thursday Turn in 2.3 Notes 2.4 Notes Egg vs Pop

2. Your Sense of Hearing

3. Parts of the Ear Eardrum: a thin membrane across the opening to the middle ear; the sound waves make the eardrum vibrate. Three tiny bones of the ear: ◦ Hammer ◦ Anvil ◦ Stirrup

4. Parts of the Ear Eustachian Tube: connects the middle ear with the back of the throat and nose. Oval Window: covered by a thin membrane that vibrates when the stirrup vibrates. Cochlea: a spiral tube containing receptors that sense vibrations.

5. Balance Semicircular Canals: curved tubes in your inner ear that help provide your sense of balance.

6. Common Ear Problems Ear infections: occur when bacteria or viruses travel from the nose or throat, up the Eustachian tube, and into the middle ear. Can be cured with antibiotics Hearing Loss: in most cases, caused by an infection, an obstruction or nerve damage. Damage to the nerve cells in the cochlea also causes hearing loss. This type is permanent and cannot be corrected. Most common cause: prolonged exposure to loud sound. Audiologist: a person who specializes in the diagnosis and treatment of hearing problems.

7. Caring for Your Ears Hearing loss can result if your ears are not properly cared for. Don’t use a cotton swab to clean the inside of your ear. Inserting an object can push wax further into the canal and block your hearing. Limit your exposure to loud sounds. Loudness is measured in decibels. 85 to 90 decibels sounds become damaging.

8. Common Noises Near total silence - 0 dB A whisper - 15 dB Normal conversation - 60 dB A lawnmower - 90 dB A car horn - 110 dB A rock concert or a jet engine - 120 dB A gunshot or firecracker - 140 dB

9. Lesson 2.4 Questions In which part of the ear are vibrations converted to nerve impulses that are interpreted as sound? Identify three causes of hearing loss. The Eustachian tube connects the middle ear with the back of the throat and nose. What is the function of this connection? How could it contribute to an ear infection? How is loudness measured? How can you protect your ears?