If a party or witness cannot readily hear, speak, or understand the spoken or written English language, and applies to the administrative unit in advance of the hearing for the appointment of a qualified interpreter to assist that party or witness, the administrative unit shall appoint a qualified interpreter to provide assistance during the hearing. With the approval of the administrative unit, a party who intends to offer the testimony of a witness who cannot readily hear, speak, or understand the spoken or written English language, may arrange for a qualified interpreter to assist the witness. An interpreter shall take an oath or affirm that the interpreter will accurately translate.