People watching - laughter

Actually this should be labelled "people listening" rather than "people watching". 

I heard an unusual laugh at the restaurant Wednesday.

The woman at the next table from me had a laugh that was loud and screechy.  I had to look to see if it was authentic or if she was doing it for another reason. It was a real laugh.  She was enjoying a conversation with a young man, and he was smiling, obviously enjoying her laughter.

Then someone pulled out a chair across the restaurant. The chair made a very loud scraping sound on the floor.

And it sounded exactly like the woman's laughter.