Where the examining or opposition division holds hearings for the purpose of taking evidence (see E‑IV, 1.3) or if the case in question is expected to give rise to particular legal issues, it is advisable that the division be enlarged by the addition of a legally qualified examiner, if this is not already the case (see D‑II, 2.2).
The evidence of witnesses is normally taken at oral proceedings either on the premises of the EPO or by videoconference. A party, witness or expert can even be heard by videoconference if the oral proceedings are otherwise conducted on the premises of the EPO. For details see OJ EPO 2020, A135.
Where a hearing is held in connection with oral proceedings, the considerations set out in E‑III, 8.2, E‑III, 8.3, E‑III, 8.9 and E‑III, 8.10 are directly applicable, and where this is not the case they apply mutatis mutandis.
The hearing of an "expert" in the sense of Rule 117 requires as a precondition a decision to take evidence (see E‑IV, 1.4). This is different from hearing oral submissions by a person accompanying the representative during oral proceedings, which can be allowed at the discretion of the division (see G 4/95 and E‑III, 8.5).