What describes how the human ear perceives the amplitude of a sound wave?

The perception of the amplitude of a sound wave is defined as loudness. When the amplitude of a sound wave increases, the sound is perceived as being louder. This is because louder sounds create larger fluctuations in air pressure, which our ears interpret as increased intensity of sound. Loudness is measured in decibels (dB), and it is important to note that while amplitude refers to the strength or height of the sound wave, loudness is the human perception of that intensity.

Pitch, on the other hand, relates to the frequency of the sound wave and determines how 'high' or 'low' a sound is perceived. Tone usually refers to the quality or character of sound, which encompasses factors like timbre. Frequency indicates how many cycles of the sound wave occur in one second, which corresponds to pitch, not loudness. Understanding this distinction helps clarify why loudness accurately describes the perception of amplitude in sound waves.