"I know," she said, her tone betraying some little sadness at this fact.

My own tone must have betrayed my impatience and anger.

However, the tone of the document betrays that assessment.

The tone in her voice must have betrayed her doubts, but the man just grinned.

His trousers and his tone betrayed him as a liar.

His tone betrayed that the thought hadn't registered fully until then.

His tone betrayed that he had already made his decision.

The tone of his voice and his eagerness had betrayed him.

The tone betrayed a common horror at the very idea.

His tone did not betray the smile that had come to his lips.