Presbycusis is a condition affecting the hearing of many adults. There are a variety of causes, including damage to structures of the middle and inner ear. The result is loss of hearing-not complete deafness, but difficulty in detecting certain sounds within the normal range of hearing. The consequences may be significant: It may be difficult to engage in conversation with others, listen to music, or enjoy watching television or movies. Current treatment, usually in the form of a hearing aid, does not usually restore hearing completely, leaving the patient with a permanent (and sometimes worsening) disability.
To prepare for this assignment:
Review the information about hearing in Chapter 9, paying special attention to the structures in the middle and inner ear as well as how sound is transmitted and processed.
Review the NIDCD Web site for more specific information about the causes and consequences of presbycusis.
Think about the implications of having presbycusis.
The assignment: (1-2 pages)
First, explain how normal hearing occurs. Include in your discussion the following points:
How is sound transmitted from the environment outside the body to the inner ear? What structures are involved, and how do they transmit sound?
What happens in the inner ear (cochlea) when sound waves are converted to neural signals? How is sound frequency (pitch) processed?
Next, summarize the causes of presbycusis and explain how they will interfere with the normal processing of sound as outlined above.
Discuss one source of presbycusis involving a problem with the outer/middle ear.
Discuss one source of presbycusis involving a problem with the inner ear.
Finally, describe what it might be like to have presbycusis. Include the following points:
If you have normal hearing now, how would your ability to converse with others be affected?
What activities that you now enjoy would be limited by this condition?
How would such a condition affect your work life?
Support your Application Assignment with specific references to all resources used in its preparation. You are asked to provide a reference list only for those resources not included in the Learning Resources for this course.
Resources to use:
Readings
Course Text: Garrett, B. (2015). Brain and Behavior: An Introduction to Biological Psychology, (4th ed.). Los Angeles: Sage.
Chapter 9, " Hearing and Language" (pp. 263-284 only)
Chapter 10, " Vision and Visual Perception" (pp. 303-337)
Chapter 11, " The Body Senses and Movement" (pp. 339-352 only)
An article from the Walden Library that discusses a disorder covered in the book. The article must be a research report or other scientific article.
Web Sites
Presbycusis
http://www.nidcd.nih.gov/health/hearing/presbycusis.asp
This site, by the National Institutes of Health, contains information about a common cause of hearing loss in adults.
Place Analysis of Auditory Frequency (Brain and Behavior, Figure 9.10)
http://www.sagepub.com/garrettbb2study/animations/9.10.htm
This sequence demonstrates how the basilar membrane responds to sounds of different frequencies (place analysis).
Sound Localization (Brain and Behavior, Figure 9.18)
http://www.sagepub.com/garrettbb2study/animations/9.18.htm
This sequence shows how neural connections to coincidence detector cells in the olivary nucleus allow sound localization.
Visual Projections to the Cortex (Brain and Behavior, Figure 10.4)
http://www.sagepub.com/garrettbb2study/animations/10.4.htm
This sequence traces the route by which the eyes send information to the brain.
Visual Detection of Edges (Brain and Behavior, Figure 10.20)
http://www.sagepub.com/garrettbb2study/animations/10.20.htm
This sequence demonstrates how on-center/off-surround retinal ganglion cells respond to edges and how these responses affect simple cells in the primary visual cortex.