Place theory and frequency theory are two fundamental concepts that explain how we perceive pitch, which is the quality that makes sounds seem higher or lower.
Place Theory: This theory suggests that our perception of pitch is determined by the specific location along the basilar membrane in the cochlea that is activated by a sound wave. Higher frequencies stimulate the base of the cochlea, while lower frequencies stimulate the apex. Thus, the pitch we hear is linked to where the sound waves cause the most significant vibration along this membrane. For example, when we hear a high note, it’s because that note is energizing a specific area near the beginning (base) of the cochlea, leaving a different area (apex) for lower notes.
Frequency Theory: In contrast, frequency theory posits that the perception of pitch is determined by the rate at which the auditory nerve fibers fire in response to the sound wave. According to this theory, lower frequencies can be tracked by the firing rate of the neurons, meaning that neurons can fire at a rate that matches the frequency of a sound wave. Thus, a sound wave with a frequency of 100 Hz would produce action potentials at a rate of about 100 times per second. This theory works well for lower pitches but struggles to explain how we perceive higher frequencies, where individual neurons cannot fire quickly enough.
In conclusion, while place theory focuses on the location of stimulation and is particularly effective for explaining high-frequency sounds, frequency theory emphasizes the timing of neural firing and is more suitable for understanding lower pitches. Both theories contribute to our overall understanding of how we perceive pitch but are most relevant in different frequency ranges.