I understand what it does -- like I said, it acts as an amplifier. But like I described, it's silly because 1. you need a frame of reference for it to be useful (meaning you need to know what the drive sounds like "normally"), and 2. every drive sounds different due to platter (thus actuator arm) count and underlying drive mechanics (ex. spindle motor brand) as well as underlying features (ex. NCQ in use or not).
Furthermore, again like I said, the OP can hear the clicking without
the use of a screwdriver-as-an-amplifier. It happens occasionally, which means what, he's going to sit with his ear against a screwdriver all day when trying to use the PC? Come on. The noise that is most commonly heard from that distance, which is occasional as well, is the sound of the actuator arm hitting the plastic or metal stop inside of the drive (either inward or outward). This is described in the "click of death" video above (though I want to make clear, the "click of death" is not necessarily applicable here -- I'm just using the term loosely).
If the drive had a bad bearing, he would be hearing this noise constantly
, not occasionally/intermittently.
All he has to do is take each disk out of the case/chassis (which he'd have to do anyway to apply a screwdriver tip to the metal casing of the drive!), and eventually he'll figure out which one is causing the noise. Troubleshooting 101 without making things overly complicated.
Let's also not forget that there's no actual hard evidence at this point that a hard disk is the cause of the noise (could be any number of the things I listed off in my last paragraph
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.