Is it obligatory to complete ablution or prayer upon hearing a sound from the anus, without being certain of the emission of gas, knowing that these sounds and gases only appear during ablution and prayer?

If you are mostly certain that no wind has exited, then your ablution (wudu') and prayer are valid and not nullified, and it is not prescribed for you to repeat ablution more than once. This view is in agreement with the majority of scholars. However, if you intentionally expelled wind, or if wind certainly exited you, then your ablution is nullified. It is advised to stay away from obsessive whispering (waswasah) and to treat it by ignoring it.