First, people don't always know. Actually I think people frequently don't know. It's not like estate/rental agents are known for their outstanding honesty. In

First, people don't always know. Actually I think people frequently don't know. It's not like estate/rental agents are known for their outstanding honesty. In California, agents (and homeowners) are required to disclose any known issues with the property, which includes neighborhood noise issues like proximity to an airport. When I bought a house located near a small airport, the selling agent had a separate airport disclosure document that I had to sign.