This is much tricker than just putting your lips together to make a 'p', 'b', or 'm' sound. When children learn this sound, they might substitute a 'd' sound, which is made with the same tongue ...

Since it uses sound waves ... time,” says Luke Burleson, M.D., an assistant professor in the Department of Emergency Medicine who co-directs STP 2233 with Resuehr. Each August, medical students have ...