Noise reduction -why the rage now ?

You were hearing something else. The science says we cannot hear RF directly. But as I described above, it could be getting into the circuits and getting amplified.

Um, yeah, no, that's exactly what I was hearing. Its called AM radio. Amplitude Modulation. The Radio Frequency is beyond the range of hearing. But it is modulated. Do you know what that means? It means its not all the same amplitude. Volume. The frequency stays the same but the amplitude of the frequency changes.

The rheostat coil and the crystal tune the RF signal in the wire to some specific radio frequency. When this happens you do not hear the RF itself. What you hear is the modulation in the amplitude of the RF signal. That's how radio works. Its a fact. You could look it up.

Sorry OP but I only have so much patience. You need to try. At least a little. Go back and read it again. Thanks!

No wait, seriously, I have to ask. How in the world can you be so arrogant as to tell me, especially after that explanation, that I did not hear what I in fact heard? From a science project designed and intended to accomplish that exact task? Without so much as a question or doubt? That is arrogance, right? Want to be sure and use the right word. Arrogant. Is there a better more apt term for it?

Yeah okay so I just asked a doc here and he made one as a kid. He's 10 years younger than me. So the intense dumbing down happened after that. 

geoffkait is right about RF. Radio Frequency (RF) is in the mega- and giga-hertz, way above sonic, and even ultra-sonic, both of which are in the kilo-hertz region.

That alone doesn't mean it can't create a problem we can hear. A common Boy Scout science project in the 60's was to build a crystal radio. Wire and crystal, you got a radio. Self-powered. String a wire from the garage across the yard into the upstairs window. Wrap the end around and around an empty roll of toilet paper. At the other end is a crystal. Forget what that was, I was a kid. But it was necessary. The wrapping is a crude coil rheostat.

Radio waves that are everywhere all the time cross the wire, inducting a tiny bit of current in the wire. A current that varies at radio frequency, too high to hear. Just exactly the same as FM (frequency modulated) or AM (Amplitude modulated) radio. Heck you can even look at an old analog radio, it says right on it MHz, so KZOK is 102.5 mega-hertz.

I forget if its the crystal or the rheostat, but either way its just static until you tune to a particular frequency. Anyone ever tuned an old analog radio should know about static. Then when you get it right, when your wire is tuned to a particular radio frequency, then out comes sound.

Which in the Boy Scout radio is barely enough energy to vibrate the toilet paper roll if you hold your ear real close. Which you can scoff with your modern high end rig but is pretty freaking cool when you are like ten.

Okay so anyway sorry for taking so long but as you can see they have so dumbed down education that stuff a kid used to learn in Boy Scout is now beyond the education of a theoretical physicist.

Because it should be pretty obvious by now, but its not, so I'll continue explaining. So now instead of one wire across the yard we're talking about lots of wires tangled around going everywhere from the coil in the cartridge to the phono lead to the ... well you get the idea. The wire goes into the phono stage where it gets amplified 45-65 dB which is a lot. And out comes.... static and.... some damn radio station! WTF!?!?

If you haven't had this problem goody for you. I sure have. A lot of people have. So it should be pretty obvious that RFI is a thing you can hear. With your ears.

Now a bit of a conceptual leap, same thing is happening in every wire everywhere all the time. And yeah you are not gonna hear it because you can't hear mega-hertz. Until and unless something comes along and tunes the radio frequency, which could be any damn thing. 

See? Its actually pretty easy to see how RFI can be audible. I mean, if a 10 year old Boy Scout can get it....

Perspective: is it really a "rage"? "Now"?

This was something I've been working on since the early 90's, having been a subject among serious audiophiles since long before that. It was around that time when I first went out and flipped all my breakers off to see if it really would make any difference. The improvement was huge, and being so easy for anyone to do its been my standard recommendation ever since. 

There are many different kinds of noise. Its not all noise like the hiss you can hear at idle even when nothing is playing. That seems to be the noise the average guy complains about and does everything they can to get down to absolute zero. When in fact the worst kind of noise is the sort that gets interwoven right into the signal. It can be called smearing, it can be called grain, but whatever its called it does not belong and therefore its noise.