The topic seems to have sparked some interest.
Rob @RobDickinson
Yes, some sort of octave shifting pedal had to be involved.
Yes, I googled it as well and came up with a similar list, however a comprehensive description of what it was being used, it was white and small, only kidding.
I was not very close and seemed to have a touch pad, to turn on/off and a single dial, not multiple dials. Not been able to track down the actual pedal on the internet yet.
I have looked at the Cher video you identified, never realised before the trickery that goes on.
Silva @Silvia80
They do say you learn something every day.
David @BurnsRhythm
As you say not really any good for us, I think you have to have a good and controlled singing voice to make use of it.
JK @jkahn
As I said I have lived a sheltered life when it comes to modern day musical effects.
I think you are right in that you need to be a very good singer to make it work, as I can imagine it is a bit disconcerting to be singing and what you hear is quite different to your normal voice.
Craig @CD02
Will have to track downs some of Ron’s songs.
Mark @markr31
See my earlier comment back to Rob, don’t think what i saw was among these
Franz @franzek
I do remember Jeffs Billy Idol cover, but the technicalities of what he was doing were way beyond my understanding.
Darrel @DarrellW
You mention Cher, it is like photos these days you can’t believe what you see anymore and the same with singing.
I would say the pedal was doing more than one octave change, given that he was probably baritone or tenor then to go up to soprano is quite a few octaves.
He did Eurythmics Sweet Dreams Are Made of This, a song I know very well and if I shut my eyes, I would swear it was Annie Lennox singing.
Jeff @nzmetal
The man himself with TC Helicon.
Does it make small changes or is capable of significant changes in octaves and do you find it a little strange hearing yourself back although I do know that what you hear within yourself is not what other people hear.
Stefan @SgtColon
Visual effects definitely matter!!!