Grande sonnerie is a complication

Complication (horology)

In horology , complication refers to any feature in a timepiece beyond the simple display of hours, minutes, and seconds.A timepiece indicating only hours, minutes, and seconds is otherwise known as a simple movement...

 in a mechanical watch

Mechanical watch

A mechanical watch is a watch that uses a mechanical mechanism to measure the passage of time, as opposed to modern quartz watches which function electronically. It is driven by a spring which must be wound periodically...

 or clock

Clock

A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece...

 which combines a quarter striking

Striking clock

A striking clock is a clock that sounds the hours audibly on a bell or gong. In 12 hour striking, used most commonly in striking clocks today, the clock strikes once at 1 AM, twice at 2 AM, continuing in this way up to twelve times at 12 noon, then starts over, striking once at 1 PM, twice at 2...

 mechanism with a repeater. On the quarter-hour, it strikes the number of hours audibly on a gong

Gong

A gong is an East and South East Asian musical percussion instrument that takes the form of a flat metal disc which is hit with a mallet....

, and then the number of quarter-hours since the hour on a second gong. In addition it can strike the hours on demand, at the push of a button. The term is sometimes used erroneously for a mere quarter striking mechanism.

It is more complex than the petite sonnerie, which merely strikes the hours on the hour and the quarter hours on the quarter, with no repeater function.