47 CFR 1.364: Testimony by speakerphone.

(a) If all parties to the proceeding consent and the presiding officer approves, the testimony of a witness may be taken by speakerphone.

(b) Documents used by the witness shall be made available to counsel by the party calling the witness in advance of the speakerphone testimony. The taking of testimony by speakerphone shall be subject to such other ground rules as the parties may agree upon.