Well I'm pretty sure it's Brian Cox's voice I'm hearing:

http://www.guardian.co.uk/science/2008/jun/30/cern.particle.physics2

The audio's at the bottom.

You've gotta love the correction:
· This article was amended on Tuesday July 15 2008. We claimed that the LHC will be the coldest place in the universe. The super-conducting magnets are cooled to 1.9 degrees above absolute zero (1.9K or -271.3C), but some low-temperature physics experiments can achieve temperatures of one-billionth of a degree above absolute zero. This has been corrected.