Mark Bullingham, the chief executive of the Football Association, has raised the prospect of the game’s global rule-making body examining whether audio between referees and VARs should be available live
It should be: no audio while they are reviewing the play. Audio while the decision is being communicated and explained to the referee.
Eg. "The player in question has been ruled offside, as the arm of the player X was past the offside line of the defenders Y foot. Goal is disallowed for offside".