This reminds me of an old Wired interview with Danny Hillis when he developed a system called Babble that used unintelligible vocal bits as background sound to help concentration, too bad it never really went anywhere. https://www.wired.com/2005/06/applied-minds-think-remarkably...

For me that would be the worst kind of distraction: always triggered by sounds of communication, never able to recognize what is said.

I suspect not all such statistical results apply uniformly to all people.

A number of noise generators have that sort of nonsensical babble as a component of the sound. For instance

https://mynoise.net/NoiseMachines/cafeRestaurantNoiseGenerat...

Nothing that your mind has enough edges on to try to interpret, but vaguely human-like.