3 ms·Didn't EM say it wasn't pressurised? Could be misdirection, mind.by bencollier49 13y agoDidn't EM say it wasn't pressurised? Could be misdirection, mind.wcoenen 13y agoNo, he said that it is "not an evacuated tunnel".dedward 13y agoThe pressure peaks in a sound wave don't really equate to a pressurized tunnel.. just a localized pressure gradient moving at the speed of sound.