NBC suit
An NBC (nuclear, biological, chemical) suit, also called a chemsuit or chem suit or chemical suit is a type of military personal protective equipment. NBC suits are designed to provide protection against direct contact with and contamination by radioactive, biological or chemical substances, and provides protection from contamination with radioactive materials and some types of radiation, depending on the design. It is generally designed to be worn for extended periods to allow the wearer to fight (or generally function) while under threat of or under actual nuclear, biological, or chemical attack. The civilian equivalent is the Hazmat suit. The term NBC has been replaced by CBRN (chemical, biological, radiological, nuclear), with the addition of a new threat, radiological, meaning radiological weapon.
NBC chimes
The NBC chimes are a sequence of three tones played on National Broadcasting Company (NBC) broadcasts. Originally developed in 1927 as seven notes, they were standardized to the current three note version by the early 1930s, and possibly as early as 1929. The chimes were originally employed as an audible programming cue, used to alert network control engineers and the announcers at NBC's radio network affiliates. They soon became associated with NBC programming in general, and are an early example of an "interval signal" used to help establish a broadcaster's identity with its audience.