That's a reposted video, the original is from Bryan Cantrill (formerly of Sun, now CTO of Joyent): https://www.youtube.com/watch?v=tDacjrSCeq4
Turned out that the BMC beeped the internal speaker which vibrated the chassis at the right harmonic frequency that matches the HDD sensitivity spot and reduced performance. After that we disconnected the speaker on all servers.
The overall nose may impact the HDD performance but mostly if the vibration is at the right frequencies. Some are a lot more important than others.