When my daughter was a baby and at that age (she has since outgrown a lot of this and it is no longer an issue)... my daughter was always sensitive to noises.
When she was in Kindergarten... SHE 'complained' about those SAME things, as your daughter is doing.
Too much noise, too loud, too many kids, all in one room etc.
And to some kids, it can just seem so 'chaotic' in the cafeteria.
And the recess after lunch, can seem so chaotic too, to some kids.
Because it is 'free play' and not all orderly. That is what recess, is.
It is, free play. The many kids just run around after lunch, although there ARE adults supervising the playground.
Anyway, my daughter was fine... although these things tweaked her.
It was an adjustment.
As parents, we have ALWAYS known... that since babyhood, by daughter was sensitive to sounds/noise. It was not in a disruptive degree... but she is just sensitive that way. She still is to a certain extent... but only when she is very tired. She is now 8 years old. So we simply TAUGHT her, to KNOW HERSELF... and to speak up in a 'nice' manner about it.
As I said, my daughter has outgrown most of this by now.
Other than that, my daughter is a normal kid, who knows herself well... and per her cues. Because we taught her that. And we know these things about her.
It was never to the degree, that something was drastically wrong with her. Nor did it impede or disrupt my daughter or her life in any way. But sure, she is sensitive to sounds. She is noise sensitive.
I am too to a certain degree. My ears, are very sensitive and it can tweak me.
Anyway, my daughter likes school, adjusted fine, has friends and is a great student.
Also, maybe your daughter is tired.... by lunch time and thus, is more noise sensitive by then. And plus with the cafeteria and after-lunch recess crowd of kids... it discombobulates her.
It is GOOD GOOD GOOD, that your daughter is speaking up and told her Teacher.
MAYBE, you can too.
AND maybe, your daughter's cafeteria seating assignment... can be adjusted so that she is sitting next to the 'calmer' kids, instead????
I would venture to suggest this to the Teacher.
In the cafeteria, the kids have assigned seating.