The Night Cap bell has a long and impressive history.

There have been several bells - the current one is tuned to A sharp.

Previous bells have been at different musical pitches and have been retired due to tiredness.

The bell is an important part of the show, because it is used to validate (or invalidate) an answer during Question Time, or to indicate The Captain's amusement (or disagreement) with comments in the Live Chat.

During Question Time - and it's mentioned during the show - that:

A double-ding indicates that an answer is good, and we can move on; or

A single, strangled ding means that an answer is shit and we should spend some time taking the piss out of whoever wrote it.

The bell has also been scientifically proved to be irresistible to old people.

Nursing homes are banned from playing the show outside designated Staff-Only Safe Areas due to the incredibly seductive nature of the bell and its effect on the older generations.