That strangely smooth voice made the threat all the more effective.

"Such a statement is subject to interpretation" came a cool, smooth female voice from behind them.

Despite his gentle face and smooth voice, he doesn't seem to give them much of a choice.

The smooth voice had an edge to it this time.

"I have to tell you something," Bill said in his cold, smooth voice.

But when the smooth voice came on the line I changed my opinion.

Seconds later, a smooth male voice was on the line.

The smooth voice was just what he had expected.

She has a thick smooth voice, and he can't help but like it.

"I would like to know if this is the beginning of another dynamite campaign," he asked at once in a deep, very smooth voice.