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.
There is no doubt that passing wind loudly and deliberately in the presence of people shows lack of politeness and bashfulness. The Prophet, sallallaahu ‘alayhi wa sallam, said: "Among the wise sayings of the previous Prophets that the people have got is: if you do not feel ashamed, then do whatever you like." [Al-Bukhari] Ibn ‘Uthaymeen said: "It is impolite to pass wind loudly." Talking about the people of Prophet Loot (Lot), Allaah The Almighty Says (what means): {And you commit in your meetings [every] evil.}[Quran 29:29] ‘Aa’ishah, Ibn ‘Abbaas, Al-Qaasim ibn Abi Bazzah and Al-Qaasim ibn Muhammad said that the people of Loot used to pass wind loudly in their gatherings, as reported by Al-Qurtubi . Ibn Hajar Al-Haytami attributed this action to the people of Loot.
Moreover, passing wind loudly hurts the attendees, and the Prophet, sallallaahu ‘alayhi wa sallam, said: "Do not hurt the slaves of Allaah, nor taunt them, nor seek their faults." [Ahmad and At-Tirmithi]
Allaah Knows best.