The Sounds of Silence is a project for the British Science Festival (11-15 September 2024).

What is silence? If we define it scientifically, silence is the absence of sound. But sound exists everywhere except in outer space, where there are none of the atoms and molecules that sound needs to travel on.

Can we create silence if we stop speaking and close our windows? No. Clocks tick. Fridge motors and boilers hum gently. Laptop and heat pump fans whir. Pipes gurgle. Timbers creak. Bird song and traffic noise comes in from outside. So do the sounds of the weather, including wind, rain and thunder. Even with the windows closed, the sounds of our neighbours and passers-by and other people’s music may penetrate too.

Our own bodies make noises whether or not we are speaking. The sounds of our breathing. The sounds of our tummies rumbling. With a stethoscope, even the sounds of our hearts beating can be heard. We can see all of the sounds of silence on an audio monitor, even if we can’t hear them ourselves. And our pets can hear much more than we can.

The sounds of silence are known as ‘ambient sound’. When filmmakers record silence indoors, they call it ‘Room Tone’. Room Tone must be included within edited films and television programmes to make the soundtrack authentic and convincing. The ambient sound or silence in every room is unique to the space and time where the recording is taking place. What can you hear around you in the room where you are now if you close the windows?

What is the best way to record the silence in a room? You can use a free Voice Recorder or Voice Memo app on your phone or tablet, or WhatsApp, or a free app like Audacity on your laptop or desktop computer. Go into the settings to make sure that the microphone is turned up as high as it will go, and that all the noise reduction settings are switched off. Remember to close your windows and doors. Then spend a few minutes listening to the ‘silence’ to see what sounds you can identify; this will help you to ensure that your recording has captured them all. If you have reduced hearing, you can see the sounds visually if you use an app like Google’s Audio Spectrum Monitor or Muzz for the Apple OS.

To join in with Together! 2012 CIC and the British Science Festival from home, close the windows and doors of the room that you spend most time in, switch off the TV and radio, and record a minute or more of ‘silence’. Upload it to your socials with the hashtag #TheSoundsofSilence – a suggested post is: #TheSoundsofSilence – here’s a minute of mine for @BritishSciFest & @ukdpctogether/@together2012cic https://www.together2012.org.uk/activities-programme/2024-events-programme/the-sounds-of-silence/