I play a druid, and more often than not, I just get out of wildshape to "talk with the party again". Not even because it's necessary, but because it gets boring trying to talk in sign language (which led me to staying silent, but that also gets boring after 30 minutes real time discussion happens which room to enter next).
As far as I know, there's no real item in dnd 5e that solves this problem. Sending stones allow only a short message, and telepathy requires a feat.
A solution I've thought is to create an item that has a special "attunement", something like:
Once attuned ~ can be given to a person (keeper). Allowing the owner/attuned person to send messages telepathic to the keeper. If the keeper can be seen and is within 60 ft.
Is this a good thingy to make? Or does it already exist? And is it unbalanced for a level 5 party to have such an item? I think the range and visibility requirement make it less abusable.