Every guardian, who shall receive on account of his ward any moneys from the government of the United States or any agency thereof, shall file with a fiduciary commissioner annually, on the anniversary date of the appointment, or within thirty days thereafter, in addition to such other accounts as may be required, a full, true and accurate account under oath of all moneys so received by him of all disbursements thereof, and showing the balance thereof in his hands at the date of such account and how invested: Provided, That in cases where the income received by the committee or guardian does not average annually more than $800, the committee or guardian may make his report of account to the commissioner once in every three years. The fiduciary commissioner shall send a true copy of each such account to the office of the bureau or other agency of the government having jurisdiction over the area in which the court is located and from which payments are made. The fiduciary commissioner shall fix a time and place for the hearing on such account not less than fifteen nor more than thirty days from the date of filing the same, and notice thereof shall be given by the fiduciary commissioner to the aforesaid bureau or other agency of the government not less than fifteen days prior to the date fixed for the hearing. Notice of such hearing shall in like manner be given to the guardian.