I used to work for HGST (now absorbed into WD) in the EMEA Enterprise Support lab. My main role was setting up PoC/testing systems, and support for high capacity SAS/helium drives, although I mostly worked with high-capacity flash boards and arrays.

The 15K rpm drives could sometimes be quite noisy; especially with 48 or more in an array.

Three of the engineers with whom I worked specialised in disk failure analysis; one of their tools was an inductive telephone earpiece pickup coil with suction cup, connected to a small amplified speaker. These guys would put the pickup on top of a drive and listen to all the electronics, spindle motor and head-moving voice coil electromagnetic noise as the drive spun up. This process would generally be followed by comments such as: "Hmm, head 4 sounds iffy", "This unit's on older firmware" and "Sounds like the heads aren't coming off the ramp"...

A lost/fading talent now that 2 out of 3 are retired". It was quite amazing to watch and listen to these guys at work.