You could tell by his tone of voice that he was uncomfortable.
At this everyone in the Throne Room suddenly became quiet, and the kitten continued, in a calm, mocking tone of voice:
All present were astonished when she appeared not only to hear a whistle, but also an ordinary tone of voice.
"You know," said the princess in the same tone of voice and still in French, turning to a general, "my husband is deserting me?
Come here a bit, said she, assuming a soft high tone of voice.
The tone of voice should be matched to the words too.