The musical hallucinosis is related, I feel, to the hyperacusis that goes with the hypo-hearing. The internal, central auditory pathways must overwork and enhance sounds...Passivity is overcome by activity.
How can this intriguing knowledge of how the brain compensates for loss or lack be applied to Opera Organically?
I believe that, for a true singer, if the expression of love that s/he must allow to flow as her voice is somehow blocked or stunted by life experience, the brain will compensate and allow for this expression in a different expression of love. His world will expand in a spiritual way or through another artistic pursuit. She will experience love in new ways and through new sensations. S/he will travel new places and log new impressions.
Until one day, when s/he looks back on it all and realizes, s/he was singing all along in some way or another, and it all lead to the truth of love and life NOW. NOW s/he can sing, not through hallucination or compensation, but as whom s/he truly IS.