Amplitude is defined as which of the following?

• A. Height of the sound wave; determines loudness
• B. The number of vibrations per second; determines pitch
• C. The shape of the sound wave; determines timbre
• D. The duration of the sound wave; determines rhythm

Answer: (A)

Amplitude is the height of the sound wave, reflecting how much air pressure varies as the wave passes. That variation is what we perceive as loudness: larger height means more energy reaching the ear, so the sound sounds louder. While amplitude underpins loudness, the relationship isn’t perfectly linear for human hearing, and loudness also depends on frequency and other factors, but amplitude is the fundamental physical property linked to how loud a sound is.

Pitch, in contrast, comes from how fast the wave repeats (frequency); timbre comes from the shape and spectrum of the waveform, which gives a sound its color or quality; rhythm comes from the duration and timing of sounds.