Jenn wrote:

"But Furtwängler's story illustrates a downside. To fill the larger halls
with sufficient sound, the voices, instruments and ensembles had to crank up
to potentially ear-damaging levels. Countless violists, who sit right in
front of the brass, have been deafened as a result.

2. The last sentence is obvious hyperbole. "Deafened"?

Yes, deafened - having their hearing capabilities diminished.
Deafness is not an absolute but a whole spectrum of impairments.

Andy