The duration of a sound is a measure of how long the sound lasts. It is the time between the start or onset, and the end, or offset, of a sound wave or vibration. The unit of measurement for duration is usually in seconds (s) or milliseconds (ms). The perception of the duration of a sound can be affected by various factors, such as the amplitude, frequency, and damping of the sound wave. In music, duration is one of the fundamental elements of rhythm, and different durations are used to create different rhythms and patterns.