Ventriloquism

Upon casting this spell, choose a point within range that you can see. Using only your voice, make a sound or speak a phrase that takes up to 6 seconds to say, and this becomes the verbal component of the spell. The sound is then projected from the point you've chosen. You yourself make no sound when casting this spell.

Any creature who hears the sound can make an Investigation (INT) check against your spell save DC to determine the source of the noise and determine if the source was real or artificial. Any creature you are hidden from that makes the check makes it with disadvantage. Any creature who succeeds on the investigation check realizes the noise was artificially created and are ineligible for the surprised condition. In addition, creatures who succeed on their check will automatically succeed on any further investigation checks against this spell for 1 hour.

Creatures that fail the Investigation check will react to the noise as if they believe it has a real source. Their reaction is up for the DM to determine based on what sound/phrase you made.