Cirrus Dishing up Data in Noise Nuisance Investigation

Noise nuisance comes in all manner of guises these days – from noisy neighbours to busy building sites, bustling bars down and household pets who don’t appreciate that silence can be golden.

The public, as a whole, are more keenly aware of their rights when it comes to a statutory noise nuisance but interpretation of what is acceptable must be decided using more sophisticated means than merely someone’s opinion.

Tony Higgins, from Enviroconsult Ltd, has more than 20 years’ experience in the acoustic services field, and uses the Cirrus Research range of sound level meters to investigate environmental and occupational noise issues.

One of his latest projects took him to a successful restaurant, which had recently expanded, and the owners needed to assess the impact of their new extraction system that was potentially causing a statutory noise nuisance.

“The restaurant had been modernised and the extraction system improved to provide extra capacity for the projected increase in business. The new extraction system was significantly bigger than its predecessor and mounted on a roof, above sensitive receptors.” explained Tony.

Based on the plant design and the key noise measurements taken by the Cirrus’ Optimus Green, Tony was quickly able to deduce there was a statutory noise nuisance in situ and introduced mitigating measures before running a post-compliance testing to confirm the improvements.

The acoustic profile was obtained from near field measurements in both cases. And the comparison feature within Cirrus software package NoiseTools™ quickly evaluated the improvements:

The first graph output clearly shows the impact of acoustically insulating the extraction system and isolating vibrating panels. A significant reduction sound level of over 25dB was achieved – testament to Tony’s experience, coupled with the accuracy of the Optimus readings.

“With the click of a button NoiseTools™ I was able to immediately show the reductions in the 1/3rd Octave frequency bands,” said Tony. “The predicted effect of the insulation I recommended was estimated to be around 15dB reduction. Turning the ducting through 90 degrees was almost an afterthought but proved to be of significant value!”

The noise from the extraction system was then assessed using BS4142:2014 at each of 5 different receptor locations, with the following results:

“The NoiseTools software and the functionality of the Cirrus Sound Level Meters were able to clearly and quickly show that the improvements made to the extraction system were effective – that translates into a happy client and a happy EHO.” concluded Tony.”