OP, was it the LNER?
We had a nightmare journey sitting behind a table of 4 children with 3 pairs of headphones… we couldn’t tell who on the train was their parents and one of the children could have been old enough to be supervising the others, so we just weren’t sure.
We spoke to the ticket inspector but he said he would only speak to an adult about it, which I guess is fair as we felt the same.
The child without headphones watched a children’s cartoon with an annoying theme song every 20 minutes, squeaky American voices and regular musical numbers for the whole 4.5 hours. All of which, I think is quite different to actual children talking or playing.
About 30 minutes before we arrived, a parent stopped by to check on the group on their way to the toilet. It turned out the two adults were sitting further down the carriage. My husband politely asked if the parents might have another set of headphones for the fourth child.
The parent went off on one like a rabid dog. They were clearly prepared for the argument and hurled abuse at my husband, who obviously regretted saying anything.
I wish LNER would make announcements to let people know it’s unacceptable. They could also sell headphones in the cafe bar and cash in on making the journey more pleasant.