Druidic Circle: Circle of Sonority
The world is loud now. It didn't use to be this way. The endless growth of mortal races has filled the world with sound, but there are those who remember how things were. There is a power in this dynamic, the shifting to and fro from loud to quiet, harsh to soft. Druids from the Circle of Sonority appreciate this relationship, using it to empower their spells and increase their understanding of all things that move.
Dampen Sound
At 2nd level, you learn how to draw in the sound around you, investing it in your body until you release it. As an action, you can choose to emit an aura out to 30 feet, centered on and moving with you, which muffles any sound within it to a quiet murmur. Creatures within this aura have advantage on Dexterity (Stealth) checks based on stealth, and resistance to thunder damage. This aura lasts up to 1 minute, you may end it as a free action, and you must finish a short rest before using this ability again.
At the end of your turn when this ability is active, you gain a charge of Vibration. You can hold a number of charges of Vibration equal to your Wisdom modifier. Unused charges vanish 1 minute after being generated.
You can expend any number of Vibration charges to deal an extra 1d8 thunder damage on any damaging spell you cast for each expended charge.
Lingering Words
At 6th level, you use your magic to tap into what happened in a particular place by listening to conversations that happened in the past. You can perform a 10 minute ritual in a quiet place to listen to any conversation which took place there in the last 24 hours.
If you are not searching for a particular conversation, the DM decides what information you uncover with this ability.
Resounding Incantation
At 10th level, you can expend charges of vibration to cast spells. You can cast a spell you have prepared in this way, but only a spell equal in level to your current number of Vibration charges. Doing so expends all your vibration charges, and ends your Dampen Sound aura if it is active.
Inaudible magic
Starting at 14th level, your spells become completely silent if you wish, making no audible noise even if they deal thunder damage or explicitly cause noise in their description. Additionally, you no longer require vocal components for spells you cast.