Petite Sonnerie

The petite sonnerie is an automatic chiming mode that strikes the quarter hours as they pass, without repeating the hour at each quarter change. This seemingly subtle distinction sharply separates petite from grande sonnerie: in the grande, every quarter hour brings with it the repetition of all hours struck up to that moment; in the petite, the hours sound only at their exact striking, and the quarters follow without reinforcement.

The mechanism works en passant, meaning it activates autonomously without the wearer's intervention, unlike the minute repeater which responds to a pusher or crown. This autonomy has a precise cost: greater energy consumption compared to silence or the minute repeater, with a measurable reduction in power reserve. For this reason, nearly all movements with integrated sonneries incorporate a selector—sliding, coaxial pusher, or on the crown—that allows switching between grande sonnerie, petite sonnerie, and silence.

From the bench, I've seen enough pieces with this complication pass through to understand that the petite is often the mode for daily wear: it consumes less than the grande, doesn't overwhelm the ear, and remains discreet. The grande sonnerie is impressive for five minutes; the petite you live with all day.

Among the manufactures that have published technically relevant interpretations: Audemars Piguet in the Code 11.59 Universelle with selection via the 3 o'clock crown, Chopard in the L.U.C Grand Strike with sliding selector, Blancpain in the Grande Double Sonnerie which uses four notes instead of the traditional two. Philippe Dufour built his reputation partly on the Grande et Petite Sonnerie, one of the rare movements where manual finishing extends to the wheels of the striking train. In total, manufacturers capable of producing a complete and reliable sonnerie movement can be counted on the fingers of two hands, perhaps one.

The abbreviation PS appears in other contexts too: in some calibers it indicates petite seconde, that is, the seconds in a subdial separate from the central index. The term should not be confused with petite tapisserie, which is a guilloché decorative motif on Audemars Piguet dials and has no relation to sonic mechanics.