All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
If a woman is certain that wind has passed out from her front passage, then her Wudhoo' (ablution) is invalidated according to the opinion we adopt here in Islamweb. In this case, it is not stipulated that she hears a sound or notices a smell; rather, the condition is to be certain that wind has passed out.
An-Nawawi said: "The words of the Prophet, sallallaahu ‘alayhi wa sallam, “until you hear a sound or notice a smell” mean: until it is certainly known that one of them (i.e. a sound or a smell) is present; but hearing and smelling are not conditions (of Wudhoo’ being ruled invalid) according to the consensus of the Muslims."
As for only having doubts and feeling of air moving or bubbles existing without being certain of passing out wind, then this requires nothing and does not invalidate Wudhoo'.
Refer to Fataawa 152333 and 85887.
Allaah Knows best.