1. Hearing Subtitle

2. The Physics of Sound  Frequency: The number of cycles a sound wave completes in a given period of time  Amplitude: the Strength of a wave

3. Anatomy of the Ear

4. From Sound Wave to Perception 1.Pinna  Tympanic Membrane (eardrum)  bones of inner ear (hammer, anvil, stirrup)  COCHLEA (primary hearing organ) 2.Cochlea is filled w/ fluid, which further transmits vibrations to thin membrane- Basilar Membrane 3.BM = Transduction; tiny hairs on BM tickle the sensory nerves 4.Neural message is sent to Temporal Lobe

5. Copyright © Allyn and Bacon 2006 How Sound Waves Become Auditory Sensations Tympanic membrane – The eardrum

6. Copyright © Allyn and Bacon 2006 How Sound Waves Become Auditory Sensations Cochlea – Where sound waves are transduced

7. Copyright © Allyn and Bacon 2006 How Sound Waves Become Auditory Sensations Auditory nerve – Neural pathway connecting the ear and the brain

8. 3 Psychological Sensations of Sound 1.Pitch- the way we sense frequency 2.Loudness- the way we sense amplitude 3.Timbre- the way we sense the complex mix of tone

9. Copyright © Allyn and Bacon 2006

10. 2 Hearing Theories 1.Place Theory: different places on the BM are responsible for different pitches- explains high pitches 2.Frequency Theory: BM fires off neural messages at different rates- rate of firing accounts for differences in neural transmissions, which result in us hearing low frequencies

11. Conduction Deafness An inability to hear resulting from damage to structures of the middle or inner ear Conductive hearing loss is often only mild and is never worse than a moderate impairment. Generally, with pure conductive hearing loss, the quality of hearing (speech discrimination) is good, as long as the sound is amplified loud enough to be easily heard. Possible Causes Ear wax build up Fluid inside the inner ear, like from an inner ear infection. If the bones of the ear get a buildup of calcium

12. Sensorineural Deafness… or Nerve Deafness An inability to hear, linked to a deficit in the body’s ability to transmit impulses from the cochlea to the brain, usually involving the auditory nerve or higher auditory processing centers

13. It can be mild, moderate, severe, or profound, to the point of total deafness. Possible Causes Long-term exposure to environmental noise Genetic Disease or illness Medications Physical trauma

14. Pre-Lingual Deafness These are people that are born deaf