I use earplugs every night for sleeping, both at home and while traveling, and have done so for a long time. The best kind for noise reduction are the foam or PVC kind that you compress/roll-up and insert into the ears. Most earplugs give their Noise Reduction Rating ("NRR") on the package, and you should look for a NRR of 32 or 33 dB. Wax earplugs usually only offer 27 or 28 dB NRR and do not work as well. You can find decent earplugs at supermarkets or drugstores, and they are very cheap. A pair of foam or PVC earplugs IME will last several weeks before you need to replace them. I order mine online from a website called The Earplug Superstore and I usually get an assortment package with a number of different styles.

One bit of advice: they take a little getting-used-to -- you need to learn how to compress and insert them properly, and you should acclimate yourself to the feeling of having them in. So get some and try them out a few times first. But with the right pair used properly, they work amazingly well and are a very cheap solution to unwanted noise.