2. Human Ear Three parts of the ear - Outer Ear Acts as a funnel to collect sounds Transmits sounds to middle ear Ear Canal Vibrates the eardrum 54
3. Human Ear Three parts of the ear - Middle Ear Vibrating eardrum moves bones Hammer, Anvil, Stirrup (smallest bones) 55
4. Human Ear Three parts of the ear - Inner Ear Vibrates membrane on cochlea Cochlea contains many small hair cells that move with the motion of fluid 55
5. Hearing Loss Conduction - Lack of transmission Earwax, calcium build-up, ruptured eardrum, otitis media, otosclerosis Sensorineural - Damage to nerves Normal aging process (20,000 receptors/ear) Often loose the higher frequency nerves first 56
6. Hearing Loss Loud sounds 80 decibels plus - Traffic sounds Signs of danger - Muffled hearing, ringing Common problems Vacuum, chainsaw, motorcycle, snowmobile, concert, bars Intense sounds - Gunshot Dangers - Antibiotics, anticancer drugs 56
8. Using Sound What are different ways that sound can be used? Dogs can hear ultrasonic sounds up to 45,000 Hz. Many animals communicate in ultrasonic sounds (mice, cats…) 60
9. Echolocation Use of reflected sound waves to determine distances or to locate objects Bats use ultrasound waves up to 100,000 Hz Use to locate insects Dolphins, Porpoises, and Whales – 150,000 Hz 61
10. Ultrasound Technology Sonar – SOund Navigation And Ranging Navigation – Finding your way around Ranging – Finding distance 62
11. Ultrasound Technology Sonogram Picture created by bouncing sound waves off of body Tissues give different kinds of echoes which can be assigned different colors About 4 million Hz 63
