And it's not just the roar of tens of thousands of people from around the world happily dancing the night away at a huge, multi-stage street party. Although there definitely is that.
Nor is it simply the spine-tingling thrill one night earlier, of witnessing a river of fiery torches flowing through the streets of the Scottish capital. Or maybe even being part of it.
It's also a river of a distinctly colder variety that welcomes a thousand brave souls, clad in fabulous costumes of course, for the world-famous New Year's Day Loony Dook - dare you do the dook?