The piece of gear used in studios in the 1970’s (primarily on vocals) was named the Aphex Aural Exciter. Is that was is being referred to here? It was a harmonic distortion generator, used by Peter Asher on the Linda Ronstadt albums he produced.
Believe it or not, Nelson Pass is currently offering a similar device! Watch the You Tube video from The Burning Amp Festival to hear him discuss it.