İngilizce Soru Bankası - uds-fen 2001-2 Soru 80

80-) It is explained in the passage that only a very small percentage of the sound waves ----.

Sounds produced by continuous vibration tones are spreads waves of compression through the air. Where there is a solid boundary such as the walls of a room the sound waves are reflected so that the sounds within the room are prolonged beyond what they would be in the open. The sounds produced by the voice or by a musical instrument then reverberate through the room after the actual tone production has ceased. When the sound waves strike the walls some of the sound energy travels on and is either absorbed in the material or may penetrate to the other side; but with the usual hard, unyielding walls of which most buildings are made, more than 90% of the sound energy is reflected back into the room at each impact, so that some time must elapse before all is spent. It is this reverberation which, in its excess, is the prime cause of the faulty acoustics of many pre 20th century buildings.