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INTEGRATION & A/V Systems
for Acoustical |
| Acoustical Countermeasures & Sound Control |
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Acoustical characteristics of any space or area are unique. In order for listeners to accurately distinguish verbal communication within meeting areas, classrooms and other venues, there are two audio characteristics that are likely to have the largest impacts:
Background noise comprises all sounds originating from within or penetrating a room. There can be multiple sources of background noise. Some can originate from the outside – including noise from adjacent rooms, vehicular traffic or aircraft. Noise from HVAC duct systems can be a major source of unwanted noise. And, problem noise that’s apparent in one section of a room may not be audible or only slightly detectable in another section of the same room. Reverberation is the time that sound waves decrease to inaudibility – after the source of the sound has stopped. Reverberation is primarily caused by reflections of sound waves from hard surfaces – such as floors, walls and ceilings. Gymnasiums for example, contain large areas of open space. When combined with the gym’s hard floor surface, reverberation can last several seconds. Alternatively, reverberation originating from within a smaller room will likely be less noticeable due to the smaller room size itself. Uncontrolled noise can accumulate causing increasing sound levels. Using sufficient quantities of sound absorbing materials can dramatically reduce reverberation and build-up. The specific types and quality of various sound absorbing materials are important as well. New construction can incorporate specific building materials, components and techniques that reduce sound problems at the onset. In many cases, the cost to 'build-in' sound countermeasures during construction can be modest – but very effective. For existing rooms and spaces, sound enhancing materials designed specifically for wall and ceiling applications can be installed. These materials fall into three categories:
Absorption materials are made from high-quality acoustic foam or special acoustic fiberglass. Acoustic foam is produced with specific cell structures and density. The foam decreases 'slap and flutter echo' – two common problems in rooms. Acoustic fiberglass is commonly used in fabric-covered panels requiring aesthetic design treatments. Diffusion materials prevent sound waves from grouping together. They can induce a compelling sense of openness within a room. Diffusion materials destroy standing waves and flutter echo without changing sound frequencies. Combining both diffusion and absorption materials can transform room acoustics dramatically. Low frequency sound waves have long wavelengths and are powerful. They can be difficult to control. And, they can penetrate adjacent walls and barriers. Low frequency sound tends to migrate and accumulate in room corners. Absorbing low frequencies requires specially designed 'bass-traps' comprising various geometries and densities – that are matched to specific room characteristics. Lighthouse Digital Media can evaluate existing rooms and spaces to help resolve undesirable noise problems and improve sound quality. 919.552.5525 |
