The word "Silsulim" in Hebrew means TRILLS.
(known from the 16th until the 19th century as "shakes").
Trills are a musical ornament consisting of a rapid alternation between two adjacent notes.
They are usually a semitone or tone apart,
which can be identified with the context of the trill (compare mordent and tremolo).
It is sometimes referred to by the German triller, the Italian trillo, the French trille or the Spanish trino.
A cadential trill is a trill associated with a cadence.
Yemenite singers use silsulim as do as some styles of Arab singers.