decay

sound

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July 20, 2026

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The term "decay" in sound refers to the gradual diminishing of sound intensity after the source has stopped. This phenomenon is known as reverberation, or residual sound, which is the echoing sound that remains audible. The time it takes for a sound to decrease to one-millionth of its original intensity is called reverberation time.12

Architectural acoustics, pioneered by Wallace Sabine, scientifically measures and predicts reverberation time. This is crucial for designing spaces like concert halls and auditoriums, ensuring optimal sound quality for listeners. The reverberation time depends on the room's volume and the sound-absorbing properties of its surfaces, such as walls, floors, and ceilings. The formula RT = 0.05V/A relates reverberation time (RT) to the room's volume (V) and its total sound absorption (A). Different applications require specific reverberation times; for instance, speech clarity needs a short reverberation time, while music performance may benefit from a longer one.34

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envelope
the attack, sustain, and decay of a sound. Attack transients consist of changes occurring before the sound reaches its steady-state intensity. Sustain refers to the steady state of a sound at its maximum intensity, and decay is the rate at which it fades to silence. In the context of…
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the attack, sustain, and decay of a sound. Attack transients consist of changes occurring before the sound reaches its steady-state intensity. Sustain refers to the steady state of a sound at its maximum intensity, and decay is the rate at which it fades to silence. In the context of…
Read More