Is there a word for somone who constantly speaks their mind? [duplicate]

In this pandemic there are a lot of people who are speaking their mind without restraint. So, I was thinking about what phrase would describe that. I felt it had to do with like “open spout" or "faucet” but something of that ilk.

“There are those who are more measured and restrained, and then there are those _____ who only speak their mind.”

I believe the term conveys a negative connotation and is something in the neighborhood of an object that emits something, and is a popularly used idiom.

Solution 1:

Someone who is outspoken gives their opinions about things openly and honestly, even if they are likely to shock or offend people.

• A few republicans have been outspoken in their support for the president.

• He was an outspoken critic of prescribing Chloroquin.

• outspoken (adjective) direct and open in speech or expression : FRANK from MW

Solution 2:

How about unfiltered (M-W): not modified, processed, or refined

Examples of unfiltered in a Sentence / Recent Examples on the Web:

"That path is even more fraught for a president elected, in part, for his populist disdain for experts, a skepticism for multilateral projects, and a direct, unfiltered style of communication."

— Rob Crilly, Washington Examiner, "Trump zigs and zags as he tries to balance coronavirus demands," 12 Mar. 2020