Deadly silence

The anechoic chamber at UCL in London

There are words you don’t want to hear when standing in a tiny window-less room that resembles a nuclear bunker and, “This would be a great place to set a horror movie.” are some of them. I’m terrified and they haven’t even closed the door yet!

I’m standing in UCL’s anechoic chamber with Steve Nevard who runs the facility and Sophie Scott, Professor of Cognitive Neuroscience (and a Wellcome Trust Senior Research Fellow). I had never previously heard of an anechoic chamber, but I can now tell you that it is “a sound isolated chamber in which the walls, ceiling and floor are lined with sound absorbent material to minimise reflections”.

The walls look like rows of shark teeth that might attack you at any moment. These ‘teeth’ are in fact pyramids of fibre-glass that are so arranged to stop sounds from bouncing around – there is almost no echo or reverberation at all. In other words, the room is designed to completely deaden any sound made and it is therefore really, really quiet – a silence the likes of which I have never experienced before, particularly living in London. Until it is no longer there you don’t quite realise how much background noise there is, and its absence is extremely unsettling.

Another thing that hits you when in the room is the sense of pressure; it feels like somebody is squashing your head. However, Steve assures me there is no difference to the pressure outside, it’s just the feeling that sound and background noise – or, in this case, the absence of it – can create.

Despite appearances the room wasn’t built as a torture chamber for belligerent undergrads that miss their deadlines, but instead has a specific purpose. As Steve explained, “Although speech is normally produced and perceived in noisy and reverberant surroundings, to study it properly we need to have an echo-free, low-noise environment and that’s why we have the anechoic chamber”.

Sophie, who studies how the brain responds to different stimuli, uses the room to record speech and sounds that can be played back to her subjects while they are inside an MRI scanner. This means that the stimulus inside the MRI is controlled, so the results are specific to the speech or sounds played and not to any erstwhile background noise.

For me though, it is the ‘silence’ in the chamber that is interesting. As Steve closed the door and stopped talking, instead of a clear and complete absence of sound I could hear a faint buzzing. This, I’m told, is a very mild case of tinnitus – a foretaste of what I can look forward to in my old age!

When we finally left the chamber a colleague turned to me to say that he’d love to spend a night in there: “I bet you’d get the best night’s sleep of your life.” Personally, I’d be too worried I’d never make it out again as the whole experience made me realise that I am more than a little bit claustrophobic.

You can hear Professor Sophie Scott talk about her research on the Guardian Science Weekly podcast (fast-forward to 19m39secs).

Jen Middleton, Media Officer, Wellcome Trust

Image credit: University College London