The tam-tam is struck with various types of mallet.
The decay of a notated whole note or of a tied note is not usually damped. If eighth, quarter or half notes are written without a tie the instrument is damped with the hand as indicated by the note value.
Occasionally the tam-tam is “warmed up” in preparation for a fortissimo note; the percussionist strikes the tam-tam lightly so that it is already vibrating when the actual note is struck. This enables the tone to build up more quickly.