1.   Her voice became more shrill.

2.   His voice became gruff.

3.   His voice became low and conspiratorial.

4.   His voice had become unmistakably frosty.

5.   Stephen put his arms around her and his voice became a soft husky whisper.

6.   Stephen put his arms around her and his voice became a soft, husky whisper.

7.   -- cover in case we noticed anything on Track Two which was a small destabilisation group.

8.   He hissed at his fingertips to demonstrate his admiration, and his voice became low and conspiratorial.

9.   His voice had become almost a screech of anger and frustration.

10.   Nicolo was still smiling, but his voice had become husky.