Oyer (to hear), the ancient word for assizes; oyer of a deed, i.e., the right of a defendant to have a deed read to him, is abolished by (English) C.L.P. Act, 1852, 55.
Means a party having a right to demand oyer is yet not obliged, in all cases, to exercise that right; nor is he obliged, in all cases, offer demanding it, to notice it in the pleading he afterwards files or delivers. Sometimes, however, he is obliged to do both, namely, where he has occasion to found his answer upon any matter contained in the deed of which profert is made, and not set forth by his adversary. In these cases the only admissible method of making such matter appear to the court is to demand oyer, and, from the copy given, set forth the whole deed verbatim in his pleading, Handbook of Common-Law Pleading, Benjamin J. Shipman, 289 at 483 (Henry Winthrop Ballantine, Editor, 3rd Edn., 1923).