The problem is that "they sound exactly the same" is already pretty difficult to hack, because cerebral processes are very complex and hard to copy.

Now think about individual differences or even cultural differences between to individuals.

I've already heard people from the same corner of the world saying that Portuguese sounds like Russian...

And in Japanese the same word is used for the colours Green and Blue.

Then this

> with me saying the exact same thing

is even another layer of chaos on top of it.

> give me any starting points.

The only chance I see is to train a neural net with lots of your personal input phrases (i.e. from same speaker)

For a small number of phrases this might bring some satisfactory results...

update

... like training a dog (or maybe rather a cat) to follow spoken commands with rewards.