Laurence Payne wrote:

Pardon my hignorance.....What's an Aural exciter and what is it used
for?

The original Aural Exciter was a box made by Aphex several decades
ago. It was flavour-of-the-month for a time. I think at the
beginning you could only hire it, not buy it outright. It gave your
recordings special "magic" ;-) It was mostly even-order distortion, I
think. Probably some eq and compression as well.

ISTR to remember a 1970's Steely Dan album proudly announcing that the
sounds it contained had NOT been passed through the Aphex Aural Exciter :-)