; (2) upon request of a party, and for good cause shown, the Copyright Claims Board may issue a protective order to limit the disclosure of documents or testimony that contain confidential information; and (3) after providing notice and an opportunity to respond, and upon good cause shown, the Copyright Claims Board may apply an adverse inference with respect to disputed facts against a party who has failed timely to provide discovery materials in response to a proper request for materials that could be relevant to such facts. (n) Evidence The Copyright Claims Board may consider the following types of evidence, which may be admitted without application of formal rules of evidence: (1) Documentary and other nontestimonial evidence that is relevant to the claims, counterclaims or defenses in a proceeding. (2) Testimonial evidence, submitted under penalty of perjury in written form or in accordance with subsection (o), limited to statements of the parties and nonexpert witnesses, that is relevant to the claims, counterclaims and defenses in a proceeding: Provided, however , That in exceptional cases expert witness testimony or other types of testimony may be permitted by the Copyright Claims Board for good cause shown. (o) Hearings The Copyright Claims Board may conduct a hearing to receive oral presentations on issues of fact or law from parties and witnesses to a proceeding, including oral testimony: Provided, however , That— (1) any such hearing shall be attended by at least two of the Copyright Claims Officers; (2) the hearing shall be noted upon the record of the proceeding and, subject to paragraph (3), may be recorded or transcribed as deemed necessary by the Copyright Claims Board