Standing on my doorstep last night at 19.55 hours it was peaceful, sun still shining, birds singing and the quietest I have ever known it. Suddenly, there was a calamity of noise, clapping, whistling, bells ringing, pots and pans being beaten. The support for the NHS and other key workers around my home was incredible.
This week I was much more organised and set a sound level meter up in my garden to record the event. Now the key question to me is who was louder, Somerset or London?
Before I explain the results, a few fundamental should be understood. On the carts below the following parameters are described:
- LAeq(T) dB – this is the equivalent continuous sound level over a set measurement period. this essentially could be considered the average sound level over a set time period, which in this case is 5 minutes increments.
- LAmax(F) dB – this is the maximum noise level measured over a specific time period on the fast setting of the sound level meter.
- LA90(T) dB – This is a statistical parameter to determine the noise level present for 90 % of the measurement period.
We have a sound level meter set up in central London. This meter is currently being used for construction monitoring for a Section 61 agreement, however the site is now quiet.
The following 5 minute trace was measured at the London site:
This indicates a 83 dB LAmaxF (maximum level measured over the time period and 65 dB LAeq(5min) between 20:00 and 20:05 hours in central London, there was also an change in LAeq(5min) of 17 dB. Therefore, because of the very low pre and post levels its is clear the LAeq(5min) of this period was primarily determined by this clapping event.
Now in Somerset the following 5 minute trace was measured:
This indicates a 76 dB LAmaxF and 48 dB LAeq(5min) between 20:00 and 20:05 hours in Somerset, there was also a change in LAeq(5min) of 19 dB. Again, because of the very low pre and post levels it is clear the LAeq(5min) of this period was primarily determined by this clapping event.
As can be seen London was clearly louder, so Somerset next week you have some work to do, get your drums out and start banging!!
Blake Lucas – Director