The voice "Aura" recalls somehow one luminous mnemonic association to many people...

it is not a recent discovery, it is not a new fact that exists a deep desire of wanting to see light in the sound

Here is a piece of a page of a book written in near 1877 by the eminent german physicist Hermann Helmholtz:

Helmholtz book frontpage

By the way, this is a book that every person interested in study musical appreciation from the scientific side must read. Was this what Helmholtz meant about aura? :

Helmholtz book - part I, page 18

We must consider that in that time physicists and chemistrys discussed about the existence of the ether ... the experiment of A. Michelson and E. Moreley was still 10 years far away in the timeline in order to demonstrate the unquestionable truth about ether ... it could be interesting however to see the colorful print of ours loved musical instruments, so characteristic and individual after all.