What does amplitude determine in sound perception?

What does amplitude determine in sound perception?

• A. Loudness (perceived intensity).
• B. Color of sound.
• C. Pace of sound.
• D. Timbre of sound.

Answer: (A)

Amplitude is the size of the pressure fluctuations in a sound wave, which determines how much the eardrum and cochlear structures are driven. When amplitude is larger, the tympanic membrane and hair cells move more, producing bigger receptor signals and higher firing rates in the auditory nerve. The brain then perceives this as greater loudness or intensity. Other aspects of sound—its color (timbre), which comes from harmonic content and spectral envelope, and pace, which relates to rhythm—aren’t set by amplitude, so they don’t primarily determine loudness.

Amplitude is the size of the pressure fluctuations in a sound wave, which determines how much the eardrum and cochlear structures are driven. When amplitude is larger, the tympanic membrane and hair cells move more, producing bigger receptor signals and higher firing rates in the auditory nerve. The brain then perceives this as greater loudness or intensity. Other aspects of sound—its color (timbre), which comes from harmonic content and spectral envelope, and pace, which relates to rhythm—aren’t set by amplitude, so they don’t primarily determine loudness.