The term 'SHARP RINGING NOISE' can be summarized as a 'PING', which is a four-letter word. A PING is a sound that is usually high-pitched and ringing, and is often used to indicate the presence of an object or person. It is commonly used in computer networking, where it is used to test the connection between two computers. It is also used in sonar technology, where it is used to detect objects underwater.