Unless other provision is expressly made: 1/ whenever the law requires the judge to hear either both or one of the parties, the promoter of justice and the defender of the bond must also be heard if they take part in the trial; 2/ whenever the request of a party is required in order for the judge to be able to decide something, the request of the promoter of justice or defender of the bond who takes part in the trial has the same force.
Source: Code of Canon Law (Vatican.va)