Why do Audi cars have a unique engine sound?

I've noticed that Audi cars have a distinct engine sound compared to other brands. What makes their sound unique and does it affect the car's performance?

The unique engine sound of Audi cars can be attributed to their use of a horizontally opposed, or 'boxer', engine. This type of engine layout allows for a lower center of gravity and smoother operation, resulting in the distinct sound that Audi is known for.