Please give me some details about the "Interference" of sound, where you have two sound sources with both of then emitting sound at the same frequency there will be points in the space, where destructive interference takes place, will be completely soundless..

Interference of sound waves takes place if the waves are travelling in the same medium. The amplitudes add up when the two waves are in-phase and result in a constructive interference while if the waves are out-of-phase then they subtract up and result in destructive interference. 

As per the above question if the two waves mentioned have the same amplitude and the destructive interference occurs at a particular point in space then it is for sure that the mentioned point in space will be completely soundless.