(a) When a conservator, guardian or trustee of a testamentary trust exhibits his or her final account to the Probate Court for allowance, the court shall appoint a time and place for a hearing on the account and shall cause notice of the hearing to be given as it directs. Such fiduciary shall sign the account under penalty of false statement.
(b) The court shall, before approving a final account of an executor or administrator, hold a hearing thereon for which notice may be given as the court shall direct, unless all parties interested in the estate sign and file in court a written waiver of such notice.