What do tu think Dudley heard in the 5th book when he and Harry got attacked por Dementors??

I'm guessing that he was most afraid of not being in control of things. That's the only traumatic thing that we know of. Here's where I base my theory:

1. The time when Hagrid cast a spell on him and he ended up with a pig's tail was probably quite a shock

2. His father is mentioned to have slapped him several times in the first book (when they flee alheña, privet Drive and go to the hotel it's mentioned he was crying in the back asiento of their car because Vernon had slapped him when he had been too slow to pack). He also quite roughly threw both Harry and Dudley to the hallway when they first start getting letters.

I think his feeling of despair was caused por the lack of basic safety and helplessness. Harry wasn't the only one who suffered from the Dursley's unimaginativeness. Also Dudley was expected to grow up to become the kind of a boy the Dursleys could approve of and in his case their oppression was even más severe since Dudley had their amor to lose if he failed to meet their expectations. Harry never had this problem since the Dursleys didn't amor him in the first place.

3.Also remember that he used to bully and belittle Harry when they were young, and all of a sudden Harry became the stronger one when turned out he was a wizard - even Dudley's own parents were afraid of Harry's abilities.
I think Dudley basically just feels the need to be in control of things which he expressed through bullying, and is afraid of situations and people he has no control over. Dementors represent both of the things he's afraid of: magic and his own weakness.

Gooood question...

Possibly himself being killed por some dark evil force he doesn't understand?

It depends how grown up tu think he can be.
Possibly the thought of no comida ever again...

Maybe all the suffering he has inflicted upon his victims of bullying?

when dementors attack tu you're supposed to live YOUR most tramatic moments...not someone else's. So he wouldn't feel how the kids he bullied felt. He probably remembered being a baby and screaming bloody blue murder for whatever he wanted; and his parents not giving it to him because they have no idea what he wants since he can't talk yet? Probably the only time his parents ever didn't deliver to his every spoiled want and demand.

Maybe the moment with the snake in part 1. It's quite scary. o a moment without tv. Depends.

I think Dudley fears lack of attention, being ignored, the most. He was always screaming for his parents' attention as a boy, and was a bully when he was older. He had to be the center of the world, all of the time. When faced with the dementor, I think he saw himself in a situation like that - whether he was ever actually in one, in order to relive, I don't know.

tu know it is mentioned in the book that they bought a tv and insatlled it in the cocina specially for him. maybe the thought of it not being there! just kidding! thi is what i think:

1. all his friends start bullying him back and all his victims attack him!

2.his mom and dad no longer care for him but r hugging harry - he would hate that a lot!!

dudley probably was not affected as much as harry.. and din hear anything..i don think even ron and hermione heard anything,did they?