What is the ruling on one who takes the apparent meaning of the Prophet's saying, "He should not depart until he hears a sound or perceives a smell," citing the narration of al-Tirmidhi, and is it permissible for him to follow contemporary scholars who say this, and what is the ruling on his prayer according to you?

The prayer is invalid and must be repeated by anyone who is certain that wind has exited, even if they did not hear a sound or smell an odor; because ritual purity is nullified by the exit of wind, by consensus. Comparing this to a woman with irregular bleeding (mustahadah) is a comparison with a fundamental difference, unless the worshipper suffers from continuous wind incontinence ( سلس الريح), in which case their prayer is valid.