Sound Insulation ~ sound can be defined as vibrations of air which are
registered by the human ear. All sounds are produced by a vibrating object
which causes tiny particles of air around it to move in unison. These displaced
air particles collide with adjacent air particles setting them in motion and in
unison with the vibrating object. This continuous chain reaction creates a
sound wave which travels through the air until at some distance the air
particle movement is so small that it is inaudible to the human ear. Sounds are
defined as either impact or airborne sound, the definition being determined by
the source producing the sound. Impact sounds are created when the fabric of
structure is vibrated by direct contact whereas airborne sound only sets the
structural fabric vibrating in unison when the emitted sound wave reaches the
enclosing structural fabric. The vibrations set up by the structural fabric can
therefore transmit the sound to adjacent rooms which can cause annoyance,
disturbance of sleep and of the ability to hold a normal conservation. The
objective of sound insulation is to reduce transmitted sound to an acceptable
level, the intensity of which is measured in units of decibels (dB).
The Building Regulations, Approved Document E: Resistance to the passage of
sound, establishes sound insulation standards as follows
E1: Between dwellings and between dwellings and other buildings.
E2: Within a dwelling, ie. between rooms, particularly WC and habitable rooms,
and bedrooms and other rooms.
E3: Control of reverberation noise in common parts (stairwells and corridors)
of buildings containing dwellings, ie. flats.
E4: Specific applications to acoustic conditions in schools.
Note: E1 includes, hotels, hostels, student accommodation, nurses' homes and
homes for the elderly, but not hospitals and prisons.
Sound Insulation