A couple of months ago I had the wonderful stereo effects of a woman laughing incredibly loudly with her headphones on in F on BA, with noisy and unruly children nearby as well (IMO noisy children are much worse than screaming babies because they can be louder - and there was no attempt by parents to control them).
To be honest it caused me quite a lot of distress as it was a long flight and I was very tired when I boarded but they prevented me from sleeping. No amount of ear plugs/noise cancelling ear phones etc could block the noise.
Then there was a hellish flight on AA in F when a child threw up and his mother did nothing to clean it up (neither did the cabin crew but I am not sure she even noticed). The stink was overwhelming and I had to ask the crew to do something about it.
Another one was on BA F with a drunk passenger singing extremely badly. It woke me from my sleep and it was so bad that I initially thought someone was crying.
There was another occasion when a child was screaming and throwing tantrums so loudly that I thought my ear drums were getting damaged as I was in D and the mother and child were in F in the same row. It disturbed the whole cabin and probably quite a few rows of ET as well although I couldn't see for the curtains. There was no sign of the child quietening down so I asked the mother if she (the child) was OK and it turned out that she and her lap child were op-upped to CE and separated from her husband who remained in ET. This caused the child to become upset and resulted in all this screaming.
Now, I considered swapping my seat with her husband in ET in the interest of my own hearing and passengers around the baby. But he was the window seat in the first row of ET, which I find extremely claustrophobic so I couldn't bring myself to swapping in case the claustrophobic feelings and the noise (which could still be heard very clearly there) overwhelmed me. So I spoke to the mother and then cabin crew to offer to relinquished the empty middle seat so that the child's father could sit there, so that the child may stop screaming so much.
While this reduced her screaming a little bit, it was still extremely loud for the rest of the 3+ hour flight. I must admit I was very annoyed with BA about their op-up policy, although I forgave them as there were disruptions outside their control.