Filter
Top Products
TRG-TRC007-EN 45
period three
Acoustical Analysis
notes
Finally, some of the incident sound energy (W
i
) bounces off of (or is reflected
from) the material. Reflected sound becomes especially important when the
sound source and the receiver are located in the same room.
Consider a mechanical equipment room that contains a water chiller, pumps,
and other sound sources. Often the walls of the equipment room are
constructed of masonry—either cement block or poured concrete. Neither of
these materials absorb or transmit very much of the incident sound energy,
so most of it is reflected back into the room. The reflected sound adds to the
sound coming from the source, greatly increasing the sound level in the room.
The best way to reduce reflected sound is to add an absorptive material to as
much of the walls, floor, and ceiling as possible.
On occasion, reducing reflected sound may also lower the sound levels in
adjacent spaces. Using the equipment room example, reducing the reflected
sound energy lowers the sound level in the equipment room. Given a fixed
transmission loss for the walls, this will result in a decrease in sound that
travels to the adjacent space. Said another way, if it is quieter in the equipment
room, it will be quieter in the adjacent spaces.
Reflected Sound
Figure 50