Reverberation Time RT60
Reverberation time is the time required for the sound pressure level to fall by 60 dB from its initial level. Sound waves in a room will repeatedly bounce off reflective surfaces.
Reverberant sound is the collection of all the reflected sounds in an auditorium.
When these reflections mix with each other, a phenomenon known as reverberation is created. Reverberation reduces when multiple reflections hit absorbent surfaces such as curtains, chairs, and tables. Reverberation is a key parameter when qualifying the acoustic status of a room.