Confessional – Wikipedia

The priest and penitent are in separate compartments and speak to each other through a grid or lattice… The priest will usually sit in the middle and the penitents will enter the compartments to either side of him… Confessions and conversations are usually whispered. Sometimes a confessional will be built into the church walls and have separate doors for each compartment; other confessionals can be free-standing structures where curtains are used to conceal penitents (and even the priest in some confessionals) from the rest of the church.