Critic Henry Pleasants has stated that it was a loss of physical strength and breath-support that led to Callas's vocal problems, saying, Singing, and especially opera singing, requires physical strength.
Kritik Henry Pleasants uviedol, že to bola strata fyzickej sily a nádychu, ktorá viedla k hlasovým problémom: Spev, a obzvlášť operný, vyžaduje fyzickú silu.