Is it true, that carpets and curtains/oblique drapes placed on

Is it true, that carpets and curtains/oblique drapes placed on the floor or wall Surfaces can reduce noise level? Explain briefly.

Yes, it is true, that placing/using carpets on floor and curtains on wall surface, windows, reduces noise level. This is because the curtains on wall surface and carpet acts as muffling device and absorb sounds of moderate level.