"There is" e "That is" tem a mesma pronúncia?

I am not going to give a definite answer, your doubt is my doubt (to some degree).
But I would hazard a guess, that of when speaking fast it would not have any difference (or an impercetible one). Yet, when talking slowly, then one can see
clearly a diference between the pair.
Even because when you are speaking ''that is" as a shortening of sorts, you don´t usually say it slowly, whereas with "there is" you can have it both ways (slow vs fast).
Slow like in this first following link, but then spoken fast I think it may have a "that is" sound.
Anyway, just an ESL guesswork here, let´s wait for more opinions and comments.

And well, if it´s the case (if same pronounce), one would know by the context, where the conversation is heading, the subject etc.


https://www.youtube.com/watch?v=SfewTOeDdC0

https://www.youtube.com/watch?v=VDNNSKuRu6Y

Elas não possuem a mesma pronúncia. Mas são parecidas quando faladas rapidamente.

O segundo "t" de That vira R na pronúncia e se junta ao Is, dando uma som parecido com "derês"

Já o "there is", se falado com a fonética dicionarizada, não será pronunciada da mesma forma, porque o "R" vibra!

Caso seja falada com a variante mais comum aqui no Brasil, mas que foge das regras fonéticas, ficaria igual mesmo.