Brown Note, aka "Shit your whole ass"

You generate a powerful, discordant sound as you perform for an audience. Choose a creature you can see within range. That creature must make a constitution save equal to your spell save DC. On a successful save, the spell has no effect. On a failed save, that creature shits it's whole ass. It suffers 2d8 poison damage, and has disadvantage on charisma checks for 1 hour, and any creature currently charmed by this creature (as if under the CHARMED condition) may immediately make a charisma save to break the enchantment, with advantage. For each spell level above 3rd, you may target an additional creature, adding an additional d8 damage per spell level above 3rd. Creatures who are deafened are immune to this spell.