1. © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Chapter 4Slide 1 LESSON 4.3 Hearing and Your Other Senses OBJECTIVES Explain and illustrate the human auditory system and the structure of the ear. Describe the senses of smell, taste, touch, and body position and movement.

2. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 2 The Auditory System The auditory system controls your sense of hearing. Hearing begins with sound waves— vibrations in air, water, or solid material. The number of sound waves that pass through a given point in one second is called the sound’s frequency.

3. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 3 The Auditory System—Pitch When your sensory system experiences the physical sensation of frequency, you also have the psychological experience of pitch. High-pitched sounds are high frequencies Low-pitched sounds are low frequencies.

4. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 4 The Auditory System—Amplitude Loudness of sound is a psychological experience that corresponds to the height of a sound wave, called amplitude. Amplitude is measured in decibels (dB). The greater the amplitude, the higher the decibels, and the louder the sound.

5. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 5 Table 4-3 Decibel Level of Some Common Sounds DecibelsSourceExposure Danger 180Space shuttle launchHearing loss certain within 150 feet of launch pad 140Jet aircraft motorAny exposure dangerous 120Sandblaster, thunderclapImmediate danger 100Heavy auto traffic, lawn mower 2 hours 60Normal conversationNo danger 40Quiet officeNo danger 30Quiet libraryNo danger 20Soft whisperNo danger 0Minimal detectable soundNo danger

6. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 6 The Ear The ear is divided into three major parts: The outer ear is the part you see. The eardrum is a thin, flexible membrane that vibrates in sequence with sound waves. The cochlea is the coiled, fluid-filled tube in the inner ear that contains hair-like auditory receptors.

7. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 7 Figure 4-5 The Human Ear (video)

8. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 8 Hearing Loss There are two types of hearing loss: Conduction hearing loss: when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones (ossicles) of the middle ear.outer earmiddle ear Sensorineural hearing loss: occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the braininner ear

9. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 9 Conduction Hearing Loss Occurs when there are physical problems sending sound waves through the outer or middle ear Often involves a punctured eardrum or damage to any of the bones in the middle ear Hearing aids Common treatment for conduction hearing Tiny instruments worn just inside the outer ear Change sound waves into amplified vibrations and send them to the inner ear

10. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 10 Sensorineural Hearing Loss More common than conductive hearing loss Involves nerve problems in the inner ear Often occurs because hair cells in the cochlea are damaged either by disease, injury, or aging Cochlear implant Only means of restoring hearing Miniature electronic device surgically placed into cochlea Changes sound waves into electrical signals Best candidates—young children born with hearing loss

11. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 11 New Science Sensory Crossovers (video)

12. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 12 Smell The olfactory nerve transmits neural impulses containing smell information from the nose to the brain. The stimuli for smell are airborne molecules. These molecules enter your nasal passages and reach tiny receptor cells at the top of the nasal cavity. These receptor cells then transmit neural impulses containing smell information through the olfactory nerve to the brain. Once your brain has processed these neural signals, you experience the aroma or odor.

13. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 13 Figure 4-6 The Olfactory System

14. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 14 Taste Taste buds are sensory receptor organs that contain the receptor cells for taste. Taste occurs when receptor cells in your mouth and throat trigger neural impulses to the brain. About 50 to 150 of these receptor cells are contained in each of the 10,000 taste buds that are located mainly on the tongue.

15. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 15 Taste Sensations Four most familiar taste sensations: Sweetness (mostly sugars) Sourness (mostly acids) Saltiness (mostly salts) Bitterness (mainly chemicals that have no food value or are toxic) Most taste experiences are complex and result from the combined effects of receptor cells in the mouth and nose, which produce the different flavors you experience.

16. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 16 Figure 4-7 The Tongue Map Myth Myth: Different areas of the tongue are more sensitive to one of the four primary tastes. Fact: All your taste buds detect all taste qualities.

17. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 17 The Skin Senses Skin defines boundaries with the environment. Skin is your largest sensory organ. The sense of touch is actually a combination of three skin senses: Pressure Temperature Pain

18. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 18 Pressure The stimulus for pressure is physical pressure on the skin. The entire body is sensitive to pressure. Some areas have more receptors so are more sensitive.

19. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 19 Temperature Temperature sensations depend on which type of receptor is stimulated. Whether more warm or cold receptors are stimulated depends on the difference between your skin temperature and the temperature you are feeling.

20. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 20 Pain Pain serves as a warning system that signals danger and the risk of injury. Pain can also force people to cope appropriately with an injury. The most widely accepted theory of pain is gate- control theory. Gate-control theory describes how pain signals open a neurological “pain gate” in the spinal cord and how other touch signals close the gate. Rubbing, massaging, or even pinching bruised or sore muscles eases pain.

21. Chapter 4 © 2011 South-Western | Cengage Learning A Discovery Experience PSYCHOLOGY Slide 21 Body Position and Movement Kinesthetic sense provides information about the movement and location of different parts of your body. Vestibular sense provides information on the position of your body by sensing gravity and motion. Equilibrium is another name for vestibular sense.