Study Questions: Frequency Tuning and Pitch Perception
1. Name the different theories for how frequency is encoded in
the auditory system.
2. Briefly describe the place theory of frequency coding. Briefly
discuss how the mechanical properties of the basilar menbrane relates
to frequency coding. Briefly discuss how the envelopes of vibrating
patterns on the basilar membrane change as the frequencies of pure
tones increase. Briefly describe how the basilar membrane responds to a
combination of two pure tones whose frequencies are (a) far apart, and
(b) close together.
3. Name the two measures that characterize the frequency
selectivity of individual auditory nerve fibers. Briefly describe how
bandwidths of basilar membrane (or auditory nerve fiber) response
curves vary with intensity. Briefly describe how bandwidths of tuning
(sensitivity) curves vary with frequency.
4. Compare the tuning curves generated from auditory nerve fibers
and mechanical tuning curves of different locations on the basilar
membrane. Briefly discuss the neural mechanism that accounts for their
major difference.
5. What is a tonotopic map?
6. Briefly describe the volley theory of frequency coding. Why
can it only account for perception of low-frequency tones? How would
you modify this theory to account for the coding of higher frequencies?
7. What physical property of sound determines its pitch? What is
the effect of a missing fundamental for perceived pitch? Briefly
describe the phenomenon of "periodicity pitch". What is the difference
between pitch and timbre?