Not quite. No script, even the IPA, is perfectly phonetic. Natural languages deviate in so many ways over time that this is the only possible eventuality.

Language is unconscious and you won't understand how it works until you let go of a lot of false culturally-programmed notions, and then actually study it by engaging with the work of linguists.

https://en.wikipedia.org/wiki/Coarticulation

For Hindi there are additional phenomena that will alter the sounds of spoken language in certain contexts.

https://en.wikipedia.org/wiki/Sandhi