"You altered his voice the way you altered your own?"
Shortly thereafter he underwent throat surgery, which permanently altered his voice.
Martha spoke without altering her voice or turning her head.
Castellaneta altered his voice for the character by no longer slurring.
He was speaking through a throat filter that altered his voice.
She can also alter her voice to duplicate exactly that of another person.
But Elwood had never shown any talent at altering his voice, either.
She could alter her voice, probably, easily enough.
He was also on the defensive after being accused of using too much "auto-tune" to alter his voice.
As well, he had altered his voice on his earlier records to sound younger.