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.
Silence (Ritual) 5e
Casting Time: 1 Action
Range: 120 feet
Components: V, S
Duration: Concentration, up to 10 minutes