It's called the "C" sound. It's called "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C" or "C."