Beginning today, Big Ben, the bell tower in the Elizabeth Tower at the Palace of Westminster in London, will not chime. The decision to stop the bell from ringing was made in order to protect the hearing of the workers carrying out restoration work, which is expected to last until the year 2021.
But just how loud is Big Ben, and is the decision to protect hearing worth silencing the famous, historic landmark?
At close proximity, the sound of Big Ben measures 118 decibels, which is loud enough to cause physical pain.
To make the bell chime, the copper and tin bell is struck by a hammer weighing 200kg. The bell, weighing 13.7 tonnes itself, makes the musical note “E” when struck. Four smaller bells in the tower: play G sharp, F sharp, E and B, which together play a tune known as the Westminster chimes.
Between August 2017 and 2021, conservation work will be carried out on the tower, and the Great Clock will be dismantled, cleaned and repaired.
The Trades Union Congress (TUC), which represents more than 5.6 million workers in the UK, released a statement saying that protecting workers from a 120-decibel sound was, “just plain common sense.”
The Health and Safety Executive (HSE) also said they worked with parliament and the building contractor to protect construction workers.
“People’s health should not be made worse by the work they do, so it is important that no worker should suffer any hearing loss while working on this project,” a spokesperson for HSE told The Telegraph.
“People’s health should not be made worse by the work they do”
Some people may have read that the noise emitted by some common household appliances measure up to 90dB and they may assume that 118dB is ‘not much louder’ but, that’s not the case. Decibels are measured, not on a linear scale (like a tape measure), but on a logarithmic scale (like how earthquakes are measured). This means that an increase of 10 units is an increase on the previous number by a factor of 10 (not by 10 units).
In a previous post, we explained that, on the decibel scale, zero is the threshold for human hearing: the quietest sound that can be detected by humans.
threshold of human hearing
10 times more intense
100 times more intense
1,000 times more intense
10,000 times more intense
100,000 times more intense
1,000,000,000,000 more intense
A sound that is 120 dB is 32 times as loud as 70 dB, and one trillion times the intensity of the smallest sound a human can hear. Exposure to 120dB would be painful. A sound measuring 118 decibels is as loud as a jet plane taking off or a police siren.
In addition to the volume, the other key factors which affect the likelihood of loud sounds causing noise-induced hearing loss are the proximity to the sound and the duration/repeated exposure.
So, if Big Ben continued to chime throughout the restoration of the Elizabeth Tower, those working nearest to the bell, and those working on the project for the longest time would be at greatest risk of noise induced hearing loss.
If you work in a noisy environment, talk to your Health and Safety representative about your concerns. There may be the need for hearing protection such as ear defenders or ear plugs.
You can measure the volume of noise using a mobile phone app such as Decibel 10th.
If you think your hearing has been damaged by noise, it is important to get your hearing checked by a hearing care professional.