You are sitting in a restaurant surrounded by some of your best friends. The food is great and the drinks are cold. The restaurant is gradually getting busier. Between the chatter and the background music, you begin to raise your voice to be heard by those at your table. You are not alone in this. Almost everyone else is doing the same. The background chatter gets louder and louder as everyone in the room also raises their voice to be heard. This is the Lombard Effect: the tendency for humans to raise their voice in the presence of noise.