How Do Frequency Theory and Place Theory Explain the Perception

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The Answer is The answer should include the following information: Pitch is determined by the frequency of a sound wave, and the basilar membrane is essential for the perception of pitch. Two complementary theories describe how we perceive pitch. The frequency theory suggests that the basilar membrane vibrates at the same frequency as the sound wave. There is a limit to how fast neurons can fire and so frequencies above 1,000 are not transmitted well in this theoretical framework. The volley principle suggests that hair cells fire in volleys. Groups of neurons take turns firing at a rate above 1,000 hertz. Each group fires in rapid succession, while other groups are in the resting state. In this way, impulses can be sent to the brain at rates higher than 1,000 impulses per second. The alterative theory, known as place theory, describes how we hear higher-pitched sounds above 3,000 hertz. This theory suggests that different frequencies cause larger vibrations at different locations along the basilar membrane. Higher-frequency sounds cause maximum vibration near the stirrup end of the basilar membrane, while low-frequency sounds cause maximum vibration at the opposite end. Thus, different pitches excite different hair cell populations along the basilar membrane. Higher-pitched sounds are interpreted according to the place where the hair cells are most active. Taken together, frequency theory and place theory together allow us to discriminate pitch of a sound. Frequency theory explains our discrimination of low frequencies, while place theory helps explain our ability to hear higher pitched sounds. Intermediate frequencies involve both place and frequency.

How Do Frequency Theory and Place Theory Explain the Perception

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