The school is entitled to have reasonable policies about visitors, including parents. You will have to check with them first. But if the reason they're screaming is that the place is so noisy they have to in order to be heard, or the room is just that "live", the only thing you might be able to do is have your child's hearing tested to see whether there may be any impairment, and then have a sit-down with the school administrators and suggest this may be detrimental to the children's health. If you get push-back you may need to consider hiring an attorney familiar with "school law" and related law to get your child the accommodations he or she needs.
