Building acoustics concerns the level of acoustic comfort for the occupants of buildings. Background noise levels need to be adjusted to the function of the room. Noise nuisance may come from rooms which are adjacent, above or underneath where people are talking, working, sleeping or moving around, or where machines are located. Noise nuisance may also enter the room through the facade or through the roof, coming from outside road, rail or air traffic, as well as from industrial activities going on in the immediate surroundings. Ventilation and air-conditioning systems may also be a source of nuisance.
Furthermore a suitable reverberation time and satisfactory speech intelligibility are required for dwelling, living and work areas. In larger areas such as auditoriums, theatre and concert halls, atriums, multi-purpose halls and open-plan offices, the duration of the sound waves also becomes important and an echo effect may even occur.
Studies examine facade insulation, room acoustics, airborne and impact sound insulation, noise from technical installations, noise propagation to the outside environment, sound insulation measurements for buildings, sound pressure measurements, electroacoustics, site monitoring, control and performance measurements, etc.
Office and apartment buildings are typical locations where this is applied. Specific applications include concert halls, cultural centres, court buildings, shopping centres, atriums, stations, plenary and other rooms.
Noise and vibration insulation
This involves defining criteria and requirements, dimensioning partition walls (masonry, concrete, movable walls, lightweight walls etc.), dimensioning facades and roofs (glazing, doors, sandwich panels, roof assemblies etc.), the noise impact of the surrounding area on the building (air, rail and road traffic), sound emissions from the building affecting the environment (dance halls, industrial activities etc.), in accordance with the regulations for VLAREM II, the Brussels or Walloon regions, airborne and impact noise insulation of floors (compositions, floating floors etc.), detailed acoustic descriptions, structure-related flanking noise (leaks, connections, circuit noise etc.), special designs (box-in-box, vibration-damping systems for structures and buildings, supports etc.), the impact of acoustic screening.
This involves defining criteria and requirements (reverberation time, STI, RASTI, definition, lateral efficiency, clarity, noise spreading etc.), controlling specific characteristics (reverberation times, RASTI, Clarity, Deutlichkeit etc.), running 3D simulations of rooms taking into account the spread of acoustic parameters across a surface and reflectograms at random points, determining ideal locations for loudspeakers in a 3D model, determining the sound distribution around sources using 3D simulation, optimising sound-absorbing surfaces or screens using 3D simulations, and choosing to use sound-absorbing materials.
Noise and vibration nuisance from technical installations
This involves defining criteria, requirements, conceptual aspects during the pre-design (air velocities, location etc.), calculating sound pressure levels in buildings and outside, determining sound pressure levels of equipment, determining the sound distribution around sources or buildings, sound propagation from flow and fan noise through air-conditioning ducts, sound transmission via ducts (grids, pipes, machines, enclosures etc.), designing, sizing and installing sound absorbers, soundproofing of ducts (pipes, air ducts, drains, machines etc.), sound insulation for transits throughout structures, sound-absorbing enclosures for equipment, acoustic screening structures, vibration-damping attachments (pipes, channels, machines, equipment etc.), vibration insulation for technical equipment (motors, pumps, air-conditioning units etc.), vibration transmission to structures (lifts, escalators, sanitary installations etc.), noise reduction using anti-noise devices.
The following measurements can be executed in the lab or in situ, according to the laws and regulations: control and performance measurements, measurements of sound pressure level (NR, dB(A), dB), spectral, statistical, excess levels, duration of excess level, intensity measurements, airborne noise insulation measurements, impact noise insulation measurements, facade insulation measurements, room acoustic measurements (impulse response, speech intelligibility, STI, RASTI, reverberation time, sound distribution, lateral efficiency, clarity, definition etc.), leak detection, noise monitoring, vibration monitoring, continuous and statistical sound measurements (LAeq, LA95, LA05, SEL etc.), spectral analyses (1/1, 1/3 to narrowband), vibration measurements, modal analysis and sound transmission.