Answer:
Amplitude, Kinetic energy
Step-by-step explanation:
The loudness or quietness of a sound depends on the amplitude of the sound wave. A loud voice produces a sound wave that has a higher amplitude than the sound wave that is produced by a quiet voice. The amplitude measures the maximum displacement of the sound wave.
In addition, the kinetic energy that is carried by the sound wave when the voice is louder is higher than the kinetic energy carried by the sound wave of a quiet voice.