SoundScapeIssue 0233When sound becomes noise, people get irritated and stressed. This is not only true in schools, but also in offices, hospitals and other public buildings. Poor acoustics can affect pupils' ability to learn, employee productivity and patients' ability to heal. Increased knowledge regarding the effect of a positive indoor environment has resulted in new regulations and recommendations for working environments. The most recent being the AIS Guide to Office Acoustics www.acousticguide.org. In many buildings, regulations have been introduced to ensure good acoustics, fire safety, ventilation and hygiene. Creating a modern, comfortable environment that complies with relevant regulations can be challenging, however. Good acoustics will depend on the specified use of the room and balancing a number of factors, including sound pressure levels (how loud it is); reverberation time (the amount of echo in a room); speech intelligibility and sound insulation (noise levels between rooms and the effects of noise from outside to inside, e.g. rain noise). Reverberation affects how well speech is understood and typically occurs in rooms with hard reflective surfaces. If noise levels are high enough in a classroom, students lose concentration, teachers have to speak louder and speech intelligibility and cognition diminishes. Young children are especially vulnerable to this but all ages suffer similar reactions.The main determinants of reverberation are the geometry of the room and the amount and distribution of absorbent materials. Utilising acoustic ceiling tiles, wall absorbers and/or baffles and islands will reduce reverberation and enhance speech intelligibility. For example, in a standard classroom of 130-250m3, the installation of an appropriate acoustic ceiling with high sound absorption will reduce reverberation time to a sufficient level to create good speech intelligibility. This is just one of the reasons why specialist acoustic solutions should always be used in new build and refurbishment projects, providing practical, technical solutions that work in old and new buildings alike. There are numerous issues to take into consideration when renovating older Absorbing ideas
Sound design at Churchill ParkSoundScapeIssue 0234buildings, with very different challenges to those in a new build project. Firstly, there are limitations imposed by the building's construction, which may have been carried out at a time when needs and traditions were very different from today. For example, the increased amount of service installations, such as heating, air conditioning and IT networks that need to be installed and hidden in the ceiling void, or increased requirements for acoustic regulation and fi re safety.The way we use our buildings has also changed over time, along with the architectural styles in practice today. For example, our schools have changed from being places with primarily one-way communication, where only the teacher spoke, to today's fl exible schools with open plan spaces, multi-disciplinary working, group based work, etc. Our offi ce buildings Poor building acoustics can affect pupils' ability to learn, employee productivity and patients' ability to healwere also mainly divided into single, cellular offi ces; now we mostly fi nd open plan fl exible offi ces, which encourage group interaction and discussion.Structural differences in older buildings can include low ceiling height and/or windows that typically run right up to the existing ceiling/soffi t. A traditional suspended ceiling cannot be used in these circumstances, but specialist acoustic ceiling solutions can be directly fi xed to the soffi t and still achieve good levels of sound absorption. Ceiling islands, baffl es (acoustic tiles suspended vertically from the soffi t) and wall absorbers are also a versatile alternative as they can be installed around existing structures and blend into existing room designs.Aesthetics also play a signifi cant role in renovation projects, particularly those within listed buildings where the original architecture has to be respected. For example, where there are structural features such as beams, columns and pillars, a suspended ceiling island or baffl e allows these features to be retained with the ceiling systems installed around them.Energy effi ciency is also critical and in a quest to meet environmental ratings in public buildings, architects are increasingly using thermal mass solutions. In order to optimise thermal mass it is necessary to use materials with a high inertia value, like concrete, which need to remain uncovered to allow effective circulation of air and heat exchange. But materials such as concrete, steel and glass also refl ect sound and can increase acoustic discomfort.Traditional 'wall-to-wall' suspended ceilings cannot be used to improve the room acoustics in these situations since the hard surfaces need to be left exposed. The solution is to utilise ceiling islands and baffl es that allow the air to circulate freely while absorbing sound from both sides of the panel, thereby optimising acoustic comfort.Taking into account the technical requirements and design wishes of specifi ers and designers, specialist acoustics products are available with a wide selection of edges, dimensions, surfaces and colours, offering the ability to create designs to suit any architectural or interior expression and enhance the acoustics in any environment - solutions to create spaces fi t for the future.Tim Spencer is technical manager at Rockfon. Rockfon offers a comprehensive range of acoustic solutions. These include ceiling tiles, baffl es, wall absorbers and islands, all made from a 100% Rockwool stone wool core. Rockfon products are known for their design, aesthetics and ease of installation; coupled with the key performance features of superior fi re resistance and acoustics. Additional benefi ts include dimensional stability, even in up to 100% relative humidity, and surfaces that prevent growth of micro-organisms such as mould, fungi and bacteria. Rockfon ceiling tiles are also recyclable, helping to reduce the burden on landfi ll sites and limit depletion of natural resources.