Yelling at your servers can measurably negatively affect their performance. No joke. Make sure to treat your servers with respect, and keep it quiet in the datacenter!
Perhaps there is a “brown note” for disks (“rust note”?) – some harmonic that destroys their performance; although based on what we think is happening (disk heads being thrown off track), we think this has more to do with shock force than resonance. I’m sure there are disk vendor engineers out there who know all about this (Bryan links to a good reference in his blog entry).
[Source: Sun Microsystems Blog (now Oracle)]