Assalamu alaikum

During namaz when you are reciting the surah's in a low tone, when suddenly a sound escapes e.g say you are reciting surah, and you are recitind the word nas suddendly the na comes out loud, does this invalidty the namaz, do we have to repeat again. This is happen to me so many times do not know what to do. What if the sound came out during surah Al Fatiha

Jazak-allah Khair