Question

To date, the most widely accepted theory of pitch perception is ________ theory. a. place b. volley c. frequency d. duplicity

Short answer

The answer is a. place.

Step-by-step solution

Understand the Question

We need to identify which theory is the most widely accepted for pitch perception from the given options: place, volley, frequency, and duplicity.

Review Theories of Pitch Perception

The theories of pitch perception include: - **Place Theory**: Suggests that different areas of the cochlea are activated by different frequencies. - **Frequency Theory**: Proposes that the rate of nerve impulses matches the frequency of a tone. - **Volley Theory**: A type of frequency theory, suggesting groups of neurons combine to match the frequency of a tone. - **Duplicity Theory**: Suggests using both place and frequency cues.

Identify the Most Widely Accepted Theory

The most widely accepted theory for explaining how humans perceive pitch is the **Place Theory**, which explains how different frequencies activate different places on the cochlea's basilar membrane.

Key concepts

Place Theory

Place theory is a prominent explanation for pitch perception. It suggests that the cochlea in the inner ear is like an instrument with different sections sensitive to various frequencies. When a sound wave enters the ear, it travels down the cochlea until it reaches a spot tuned to that frequency. Here, neurons are activated and send signals to the brain, telling it how high or low the pitch is.
This concept is similar to how musical instruments have strings that vibrate at different frequencies.

• Low-frequency sounds stimulate the apex of the cochlea.
• High-frequency sounds activate the base.

This breakdown of sound into component frequencies allows us to understand complex sounds, like music or speech. This theory is widely accepted because it matches the observed activity in the cochlea and explains why people can discriminate between pitches.

Frequency Theory

Frequency theory offers another perspective on how we perceive pitch. This theory proposes that the auditory nerve's firing rate is directly related to the frequency of the sound wave. For example, if a sound wave has a frequency of 500 Hz, the auditory neuron will fire 500 times per second. This helps the brain understand the frequency and hence the pitch of the sound.
However, this theory has limitations. Neurons can't fire fast enough to keep up with very high-frequency sounds. The theory is more applicable to lower frequencies, where the firing rate of neurons can match the sound frequency.
Despite its limitations, frequency theory is crucial in understanding the processing of low-frequency sounds. It also highlights the role of the neural firing rate in pitch perception.

Volley Theory

Volley theory provides an extension to frequency theory, making it applicable to a broader range of frequencies. This theory proposes that groups of neurons can work together to encode sound frequencies. Instead of one neuron trying to fire rapidly to match a high-frequency sound, several neurons take turns firing.
This ensures that collectively, they can transmit the rapid signals needed for high frequencies, while not overtaxing individual neurons. The brain then interprets this accumulated firing pattern to deduce the pitch.
It's like a team of runners passing a baton in a relay race, achieving something together that one runner alone couldn't. This theory fills in the gaps left by frequency theory and helps explain how we perceive a wider range of pitches.

Auditory System

Our auditory system plays a crucial role in pitch perception and involves several key structures. The process starts with the outer ear capturing sound waves and channeling them into the ear canal. These waves then cause the eardrum to vibrate, and these vibrations are passed to the cochlea via three tiny bones in the middle ear called the ossicles.
The cochlea, a fluid-filled spiral structure, is critical for transforming mechanical vibrations into electrical signals. It contains hair cells that respond to different frequencies by causing frequency-specific areas of the cochlea to move. The movement is then translated into nerve impulses.

• The auditory nerve transmits these impulses to the brainstem.
• Next, they are sent to the auditory cortex in the brain, where sound is processed and interpreted.

The combination of these steps allows us to understand and enjoy a multitude of sounds, from a friend's voice to symphonic music. This system is finely tuned and developed to facilitate detailed pitch perception.