It is proved that sound travels fastest through solids. However, when a T.V is switched on, the sound produced is louder without a wall between the person watching than with a wal l between the person watching and the T.V. How is this possible?

Sound produced in air will travel through air and it can be absorbed, transmitted and reflected by hard surfaces like concrete wall or wooden structure. When there is wall between the loud speaker and the man the sound from the speaker is absorbed, transmitted and reflected by the wall. As a result the sound heard is of low volume. Also the wall is not helping the sound from the loud speaker to reach the man’s ear. Sound travels faster in a solid medium compared to gaseous medium. But in this case the solid medium is acting as an obstacle to the propagation of sound.