Key ideas

• Place theory says pitch depends on where in the cochlea hair cells are activated, which works best for high pitches.
• Low frequencies activate a broad area of the cochlea, so place alone can't distinguish low pitches well.
• Frequency theory says neurons fire in sync with low-frequency waves, so the rate of firing signals pitch.
• Volley theory explains mid-range frequencies: groups of neurons alternate their firing to represent frequencies too fast for one neuron.
• Together: frequency theory explains low pitches, volley theory mid-range pitches, and place theory high pitches.

Key terms

place theory

Pitch depends on where hair cells are activated in the cochlea; high frequencies activate cells near its beginning.

frequency theory

For low-frequency sounds, neurons fire in sync with the sound wave, so the firing rate signals pitch.

volley theory

Groups of neurons alternate firing to represent mid-range frequencies too fast for any single neuron to match.

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