Silence

Silence PHB p275 2nd-level illusion (ritual) Casting Time: 1 action Range: 120 feet Components: V, S Duration: Concentration, up to 10 minutes For the duration, no sound can be created within or pass through a 20-foot-radius sphere centered on a point you choose within range. Any creature or object entirely inside the sphere is immune to thunder damage, and creatures are deafened while entirely inside it. Casting a spell that includes a verbal component is impossible there.

Classes: Bard, Cleric, Ranger Subclasses: Land (Desert) Druid, Divine Soul Sorcerer, Fathomless Warlock, Undying Warlock, Shadow Monk, Lurker in the Deep (UA) Warlock, Raven Queen (UA) Warlock Races: Gnome (Mark of Scribing) Feats: Adept of the Red Robes, Adept of the Red Robes Source: PHB, page 275. Available in the SRD and the Basic Rules.