The duration of an Arabic letter sound is measured
by a unit known as a "move." A "move" is the
unit of time required to touch one or more
fingers by the thumb.
Note: the maximum number of moves is four and any
Arabic letter needs at least one move to produce
its sound correctly.
Because "one move" entails duration of
time too brief to be captured by finger movements,
it is not described in the category below.
