Place coding of fundamental pitch fails at high frequencies when harmonics smear together

Evidence

The two versions of the place code are illustrated in Figure 6–3, which shows a schematic of the envelope of the cochlear traveling wave for a pure tone (top panel) and for a complex tone (bottom panel). The frequency of the tone in the top panel can be coded from the place of maximum excitation à la Helmholtz (a simple place model). This model can effectively explain why pitch increases with increasing stimulus frequency. Changing the frequency causes different basilar membrane locations to be associated with different peak excitation. The pitch of the complex stimulus, however, can be coded in multiple ways: (1) the location of the lowest-frequency (api- … Because the spacing between components decreases as frequency increases (as the place representation moves toward the base of the cochlea), the place code is a poor representation of the fundamental frequency at high fundamental frequencies. When the excitation peaks associated with individual harmonics are not resolved (that is, they are smeared together), the place code indicates that the pitch of the stimulus should be difficult to determine or should be very weak. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1207

Categorization

Category: Causal Relationships

• XREF: Connects to harmonic template models’ strength/weakness tradeoffs and the reader’s interest in both normal and impaired hearing perception limits (audibility of unresolved harmonics).

Related

• Place coding poorly carries pitch when harmonics go unresolved. (similarity 0.92)
• Unresolved harmonics smear together as frequency rises (similarity 0.88)
• Resolved harmonics use place pitch coding while unresolved harmonics use temporal coding (similarity 0.88)
• Place theory cannot account for level-independent pitch, so other mechanisms must operate (similarity 0.87)
• Only the first five to seven harmonics are resolved by the ear’s place mechanism (similarity 0.86)
• The auditory system can extract pitch from resolved low-frequency harmonics using place patterns (similarity 0.85)
• Pitch may be jointly coded by temporal patterns and their cochlear location (similarity 0.85)
• Place and timing theories fail to explain some complex pitch perception phenomena (similarity 0.85)
• Sloping or rising hearing loss can create contradictory pitch codes across frequency regions (similarity 0.84)
• Resolved low-numbered harmonics are required to encode pitch by place (similarity 0.84)
• The residue pitch refuted Helmholtz’s place theory of pitch percept. (similarity 0.84)
• Place theory claims pitch is encoded by basilar membrane position (similarity 0.84)
• Phase locking fails above 5 kHz, so high-pitch perception relies on place theory (similarity 0.84)
• The temporal code mainly handles pitch at low frequencies where pitch is strong (similarity 0.84)
• Auditory nerve phase locking fails at high frequencies, leaving only the place code (similarity 0.84)

Broader Connections

• The ear switches from place to temporal pitch coding when harmonics stop being resolved #expands (0.90) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1307
• Harmonics resolve only while their spacing exceeds the ear’s ERB #corroborates (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1505
• Phase locking fails above 5 kHz, so high-pitch perception relies on place theory #complicates (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 907
• Sloping or rising hearing loss can create contradictory pitch codes across frequency regions #exemplifies (0.75) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1337