(a) Witnesses at the hearing must testify orally under oath or affirmation unless otherwise ordered by the ALJ. At the discretion of the ALJ, testimony may be admitted in the form of a written statement or deposition, a copy of which must be provided to all other parties, along with the last known address of the witness, in a manner which allows sufficient time for other parties to subpoena the witness for cross-examination at the hearing.

(b) The ALJ determines the admissibility of evidence in accordance with § 134.223 (a) and (b) of this chapter.