The summer ‘look’ of a Laughing Gull is distinct, an obvious black hood. And yes, they sound like a loud laugh.
During the winter months I’m not sure you can tell the difference between this or any other plain gull. Considering this was taken in March they may have the hood all year round in warmer locations.
Unless you live on the east coast of the US or southern Canada you have probably not seen one. They stick close to the ocean.
These are the first photographs I have taken, random birds in flight excepted, of this gull. Not a bad looking bird.