[maricruzcampos (OP)]

Bree wants to know,

If a person is born completely deaf and can’t hear a thing, what language do they think in?

What do you think?

[Bored chemist]

https://www.thenakedscientists.com/forum/index.php?topic=28129.0

[katieHaylor]

This question has now been answered - you can listen to it here: https://www.thenakedscientists.com/podcasts/naked-scientists-podcast/cars-future-are-we-ready

[robertjone336]

I came across this post to share my personal experience. I have a colleague in my office that are deaf; I feel so sorry whenever I see him. I work for a freight forwarding company here in Dubai, and we have almost every nationality person that working in the same environment. I asked the same question he said that commonly it is challenging to understand, but in the start, people taught a signal to understand something, so he explained the things slowly.

[alancalverd]

Slightly askew to the subject, I saw an astonishing skill on a PBS TV show last evening. They had some silent film of soldiers preparing for a raid in the Battle of the Somme, and asked a forensic lipreader to give the men a voice. Deaf from birth, her ability to interpret the grainy, jerky film was amazing. At one point she stopped and said "that man does not have an educated accent and I'm having some difficulty with him". The  researcher said "he's from the Lancashire Regiment", whereupon she spoke his words in "deaf Lancashire" almost in real time.

So the answer is "not only in the language they have been taught, but with a preferred regional accent!"   

[EnvetteWerMar]

I congratulate, the excellent answer.

[Bored chemist]

Since this has already been bumped...
Here's another reason why  I don't believe that people "think in a language".
https://www.thenakedscientists.com/forum/index.php?topic=33220.msg317959#msg317959