Sound reduction , Architectural
Sound insulation prevents two kinds of sound transmission: airborne
sound and impact sound.
The conventional rule for reducing sound transmission is the
mass law. This says that the heavier the structure, the less sound
it will transmit. However, other factors, such as discontinuous
construction and stiffness, mean it is possible to achieve good
sound insulation levels with lightweight construction, making
the most of the drywall advantage.
One of the most important features of sound insulating structures
is that they should be imperforate. Even the smallest of cracks,
say only 0.4mm wide, has a significant area along the length of
a wall, and could halve the effectiveness of a 50dB partition.
Structures have variable sound insulation values depending on
the frequency of the sound. With Lafarge’s twin frame partitions
significant improvements can be made, especially in insulating
against higher frequencies.
Effects of sound reduction values on audibility
Rw Conversation level
30 dB Normal conversation can be distinguished
35 dB Loud conversation can be distinguished
40 dB Loud conversation can be heard but not clearly distinguished
45 dB Loud conversation can just be heard but not distinguished
50 dB Shouting can just be heard but not distinguished
In domestic buildings, acoustic factors are not very critical.
Most of the necessary sound absorption will be provided by the
furnishings and occupants. However, with auditoria of all types
the design problems are complex, and acoustic specialists should
be consulted. Despite the complexity of acoustic science, some
basic principles are universal:
• Provide direct sound paths between sound sources and listeners
– consider raking floors and try to avoid columns.
• Beware of curved surfaces – convex shapes scatter
sound and concave shapes focus it, often with disastrous results!
• Optimum reverberation times will depend on the use of
the space and will be longer for music than for speech. With unwanted
sounds, for example the noise of machinery, it is best to shorten
the reverberation time as much as possible.
Acoustic tests determine partition performance
Wizard .You can selecet type of plasterboard according
to sound & fire rate criteria
Plasterboard Sound Reduction Performances