Noise matters
Noise is just as much an environmental pollutant as spilt chemicals or harsh lighting, and can be just as damaging to employees health. It can also be damaging to visitors and others in the neighbourhood, which means that every company and organisation must take steps to monitor and reduce unwanted noise. At Acoustical Control Engineers Limited we have a wealth of experience in monitoring and managing noise.
What do we hear?
The human hearing system is complex, we hear a range of pitch (frequency) and volumes (amplitude) We have different sensitivity at different frequencies. We are more aware of noise at some frequencies than at others, and we are all different. You may need to measure sound frequencies during construction/re-development phases and in established buildings say when a new plant or printing machine is added. Noise is measured in decibels (dB) at a range of frequencies and is likely to be most annoying when its energy is concentrated in the middle frequencies. The dBA reading takes this into account.
What is the difference between absorption and insulation?
An absorptive surface does not reflect much sound, but may let all sound travel through it. A surface that provides good sound insulation does not let much sound travel through it, but may reflect most sound. Insulation is essential in order to reduce the noise breaking out from one area to another, whether this is between neighbouring dwellings, or between a plantroom and adjacent office. Absorption can reduce the reverberant (reflected) sound level within a noisy room. Whether it has much effect on the noise level transmitted to a neighbouring area depends to some extent upon the amount of absorption, but is often more affected by the position of the noise source within the room.
How can I reduce noise?
The most effective way to reduce noise is to control it at source, ideally by selecting quiet equipment or working quietly. If this is not possible, or the noise level is still too high, it will be necessary to attenuate the sound propagation path. An acoustic enclosure can be designed to provide the required sound insulation by using suitable materials and constructions. This need not be of proprietary acoustic materials but may use conventional building materials such as plasterboard or block work where appropriate. Apertures are often required for ventilation, services, or the movement of materials. In this case, noise breakout can be prevented by using attenuated air paths. Vibration isolation is often important to ensure that vibrational energy is not transmitted outside the enclosure and then re-radiated as sound.
Contact Details
Acoustical Control Engineers Limited
Broadway,
Bourn,
Cambridge.
England.
CB23 2TA
T. +44 (0) 1954 718344
F. +44 (0) 1954 718355