I propose to consider whistle blowing recognition for kick-off procedure similar to one implemented in SPL rules:
The referee will announce the start of the Playing state with a single whistle blow. The GameController Playing signal will be delayed by 15. This delay applies to both kick-off and penalty
shots. Robots that begin moving their legs or move in any fashion during set (i. e. before the referee
blows the whistle) will be penalized in place on the field via the “Motion in Set” (see Section 4.5)
GameController signal until the GameController transmits the playing signal. A robot will be
moved back to its original position if it has moved significantly before becoming penalized. Note
that responding to a whistle on another field will result in this penalty.
Can be discussed here Whistle recognition