If you’ve been in a factory, around a jackhammer at a construction site, or heard the whine of a dentist’s drill, you know already that noise is a big part of life and so many different industries. Within each of those industries and businesses, there are many reasons why it may be important to measure, monitor and record noise levels. Occupational health and safety requirements protect workers against hearing loss; managers will want to optimise sound conditions for ideal productivity; external regulations must be adhered to for noise pollution; businesses like cinemas and concert promoters perfect sound levels for the best possible experiences.
In all of these cases and so many more, organisations get their hands on the latest in the impressive and vast range of noise level meter technology, with modern devices giving instant, reliable and highly accurate decibel readings for a price every business can afford for their purposes. But how do they work? And how do the respective industries use them for ideal results?
What Is Sound, Anyway?
Decibels (dB) – in deference to Alexander Graham Bell – are a bit like degrees Celcius, in the way that without a standardised measurement like that, noise and temperature levels are completely subjective. A room that is too cold for one is perfect for another, while a motor racing aficionado will have a different attitude to a roaring engine than a mother wanting to put her baby to sleep. But there can be no arguing about the decibel reading of any particular sound event, as it’s a precise measure of the amount of energy making its way to the sound level device in the form of air pressure variations. Unlike degrees C, however, the decibel scale is not linear – it’s logarithmic. What this means is that jumps of 10dB represent an increase of ten times the sound intensity, so that 20dB is actually ten times more intense than 10dB. Once we get close to and then beyond 100dB can therefore be damaging to the human ear:
- Leaves rustle at 10dB
- Conversations tend to be about 40-50dB
- Traffic noise is at 60-80dB
- Jackhammers operate at about 100dB
- 120dB is the human pain threshold
Which Sound Level Meter Do You Need?
Visibly, a typical sound level meter is a hand-held device with a microphone at the top and a read-out – but there are various different types. A basic device will provide an instant reading, others will provide average values recorded over a period of time, and data-logging meters can be programmed to test over longer periods and provide accurate analytics. The European Union’s noise protection for workers regulations call for the use of fully calibrated integrating sound level meters that can provide average and peak values, while those measuring environmental noise should consider Class 1 or Type 1 devices that are highly accurate at lower levels. An organisation simply needing to do spot checks for fire alarm, office or machine noise, however, can get away with simple and easy to use Class 2 meters.
As ever, however, it’s crucial to check in with experienced experts in sound level technology, not only so the right device is matched with the respective application and budget, but so that the way the device is used is correct for optimal results.