An acoustic engineer is responsible for measuring sound and vibration and designing solutions to control excessive noise: they might specialise in a particular field such as environmental noise, architectural acoustics or vibration control.
Acoustic engineers are commonly required to use equipment that can pick up lower frequencies in an industrial area, e.g. where the noise and vibrations may be at a lower pitch.
Sound Level Meters
Different equipment is used to measure sound in different areas. Type 1 sound level meters and accelerometers are used for all noise assessments. These are UKAS calibrated to ensure the highest accuracy for environmental noise monitoring and vibration measurements, enabling noise source recognition and data post-processing.
A sound level meter is field-calibrated for each assessment. It has one-third octave band capability; noise and vibration channels; impulsive and tonal functionality, incorporating the requirements of British quality standards; and it also has a seven-day battery life.
The omnidirectional microphone is used in certain environments to pick up the surrounding noise from different angles. They will pick up sound equally from all sides and in any direction – rather than just the area where the microphone is pointed.
Omnidirectional microphones are advantageous over directional microphones in some situations because they allow greater flexibility for picking up sound.
Directional microphones pick up high sensitivity sounds from one specific side – picking up sounds with high sensitivity coming in from the front but not from the sides or rear. This can be advantageous when focusing towards a specific noise.
Measuring Excessive Noise
Investigations into noise nuisance are carried out in liaison with environmental health teams and local planning authorities to successfully resolve any noise related issues.
Any business or individual who fears they are making excessive noise can employ the services of an acoustic engineer to test and monitor the sound levels and if necessary, provide solutions such as acoustic walls, floors, louvres, screens and other products to control the situation.
Specialised equipment enables full scientific acoustic reports to be issued for all noise assessments, including industrial noise that affects residential dwellings; noise insulation scheme designs; new dwellings; noise at work; sound insulation tests; noise and vibration assessments; site visits and specification reports relating to sound insulation; entertainment noise; and plant room and enclosure design.
The description and measurement of environmental noise is governed by the British Standard, BS 7445. This serves as a guideline for the acoustic engineer to ensure that the necessary methodologies and procedures are followed to achieve an accurate and traceable assessment.
An assessment can be carried out for environmental noise outdoors too, with precise specifications to ensure an exact result. The assessment time and date must be carefully selected in terms of the meteorological conditions, so that the procedure can be performed in ambient conditions – without being affected by background noise.
The measurement should be gathered more than 3.5 metres from a reflective structure, with the ideal measurement height ranging from between 1.2 metres and 1.5 metres.
Acoustic engineers also use their engineering equipment in the field of architectural acoustics to design superior acoustical qualities for buildings. It’s not only concert halls and other venues that can benefit from enhanced acoustics; careful sound planning will ensure superior acoustics in day-to-day life, whether at home or in the workplace.