Alesis ADAT-XT20 Reference Manual page 83

Chapter 4: Basic Operations
82
is reached, any tracks that are in record-ready will be in input monitor
mode and the [RECORD] LED will continue flashing. When the Locate
Point 3 position is reached, any tracks that are in record-ready may
return to tape monitor mode. The [REHEARSE] button turns Rehearse
mode on and off; the REHEARSE icon will light when enabled. Note
that if Auto Input is not enabled, Rehease will have no effect on what
you hear in your monitor mix.
ADAT XT20 Reference Manual