Building an Environment for Helpful, Effective, and Accessible Representation and Decision-making Act or the BE HEARD Act This bill directs the Department of Defense to develop specific training to assist Special Victims' Counsels in recognizing and dealing with the effect of gender differences on victim response to sexual assault. The Court of Appeals for the Armed Forces may review for legal error a grant or denial of a petition for a writ of mandamus by the Court of Criminal Appeals upon petition of a sexual assault victim or the accused. Such review shall have priority of consideration to the maximum extent practicable. The bill states that: (1) the designation authority under the Uniform Code of Military Justice to appoint an individual to assume the rights of a victim who is under 18 years old or incompetent is discretionary, and (2) such designation is not required if the military judge determines that a victim who is under 18 years old can adequately represent his or her own interests.