This is a topic that I like to comment on many times due to the frustration I actually feel when hearing compliants from people on how uncomfortable they found the flying experience. As someone who sells hearing protection products for a living I can testify that this is actually something that can actually be cured very easily.
It may sound biased but all you need to do is wear a pair of decent ear plugs and this should generally do the trick. Although earplugs are giving out in flight, it appears for many users they do not actually go far enough in helping resolve this issue.
Although it is not for me to comment on the stuff airlines handout to their customers, by investing a little bit of money in supply some quality ear plugs would actually help their passengers, some of who are paying good money to fly.
Anyway I shall get off my soap box now but please do considering buying flying ear plugs for your next journey.
Regards. J.