60 second mystery

It takes just 30 seconds to read this short, short mystery. It should only take 30 more seconds to prove your 'detect ability'.

• A woman enters a taxicab.
• Cab starts off.
• Woman begins to talk.
• Driver dislikes talkative passengers.
• Woman continues to talk; asks a question.
• Driver thinks fast; points to mouth, shakes his head as if to signal he can't reply.
• Points to ears, signaling he can't hear.
• Woman stops talking.

Arriving at her destination, the woman realizes she's been hoaxed. What could make her aware of this? It wasn't necessary for the driver to speak to tell her the fare, for the taxi-meter indicated that. The driver didn't say a word to her.

Answer: Mouse over the picture.