She claimed to have been able to lift the firewood with the help of the unknown voice.

The final words are from an unknown voice: "He is the god of love."

If you are a stranger with a voice unknown to the people inside, there is no problem.

"He only typifies the basic problem," said the unknown voice.

Too distracting, far better to have an unknown voice I think.

"Things have gotten too hot for us," an unknown voice said to Po.

He did get an answer from an unknown voice that sounded like a boy his own age.

He sent back a message and a warning, through this unknown voice.

Tell me, other than hearing your name spoken by an unknown voice, do you remember anything more?

"If you're being sued, an unknown voice on the other end of the phone may not be very reassuring."