Question

what is reverbreation ........plz help me.... i need it fast

Answer 1

prolongation of a sound; resonance.

Answer 2

Reverberation of (sound) waves is the effect that is caused by multiple reflections (echos) of the waves from walls and obstacles.  These cause the effect of persistence of sound for a longer time duration than otherwise.  This is a desired effect (to a certain extent) in many cases, but in a controlled way.  The huge meeting halls and seminar halls are designed for a good reverberation.

more on it:

We can observe this effect when we are among a lot of tall buildings, among high mountains, or in a big hall (meeting hall or cinema hall).

We can hear the sound directly coming from the source and also from the reflections of the sound from nearby tall structures. The first reflection of sound takes some time. The further reflections of sound takes lesser and lesser time duration.  They also decrease in intensity too in time.

Reverberation time is the duration for the reverberation sound to be a millionth of its intensity.

The design of big halls and auditoriums needs to take care of reverberation effect. Reverberations help the people at different locations to receive sound at uniform intensity. But we do not want to have the reverberations to last very long. An optimized value will be chosen. The wall shapes, ceiling shapes, coating or plastering on walls are done according to acoustic effects such as reverberation.