Psychology 3215

Questions about Hearing to Ponder before Test 4

Fall 2021

1. Understand sound waves and the physical measures of frequency (Hertz) and amplitude (decibel). What does it mean to go from 100 Hz to 200 Hz? What does 0 dB SPL mean? What does it mean to go from 0 dB to 40 dB SPL?

2. Understand describing sound waves as sine waves. In what sense is this description accurate and inaccurate? What happens when sound waves combine?

3. Know the difference between pitch vs. frequency, loudness vs. amplitude. If you know the frequency, can you predict the pitch? (See #9.) If you know the amplitude, can you predict loudness? (See #8.)

4. Know the structure of the ear. Be able to follow the sequence from a sound wave hitting the pinna to the bending of a hair cell. Understand the different functions of the Inner Hair Cells and the Outer Hair Cells.

5. Consider the cases of a 50 Hz and a 5000 Hz sound signal. Know how these signals affect the basilar membrane and produce different pitch experiences according to the Rutherford/Wever frequency/volley explanation and the place explanations of Helmholtz and Von Bekesy.

6. What are the two types of hearing loss? How does an audiogram differentiate between the two types? What type of hearing loss is presbycusis?

7. What are the techniques that we can use to diagnose hearing loss?

8. How does a cochlear implant work?  How well does it work? What are the issues in recommending  cochlear implant.   

9. What is an audibility function? How is it produced? Know the general shape of the function. What does this tell us about hearing? Know the general shapes of the equal loudness contours for different frequencies.  How are they produced?  What do they tell us about hearing?

10. What is the amplitude-frequency shift? Know the general shapes of these contours for different frequencies. Functionally, what do these contours tell us about hearing?

11. What were Steven's scales of loudness and pitch? How were they created? Why aren't they in general use?

12. Understand the azimuth/relative bearing system for indicating direction.

13. Know how interaural intensity differences contribute to localization of sounds. Does this work with all frequencies?

14. Know how interaural time differences contribute to localization of sounds. Does this work with all frequencies?

15. The duplex theory of sound localization was tested in an experiment by Stevens and Newman. What were the results? What do the results suggest for human hearing?

16. Why do we have difficulty discriminating between a sound located at 0 and at 180 degrees? Explain why moving your head makes localizing a sound easier.

17. How does ventriloquism work? Can a person like Darci Lynne really "throw her voice"?

18.  What is timbre in a musical note and why does it happen?  What is Helmholtz's explanation of pitch and timbre?  How does the Missing Fundamental effect apply to that explanation?