Lately, I've been having increasing trouble in blocking out unwanted noise when in a noisy environment. For example, when sitting at a table with my friends in a crowded restaurant. I seem to have lost the ability to "un-focus" on other people who don't matter and focus on the people that I'm trying to talk to. This is both very annoying and quite distressing. I keep missing half the conversation, have to keep asking people to repeat themselves, and as a result have been getting stressed out and angry.
This is most likely either a manifestation of my brain chemistry being out of whack, or a side effect from a medication that I've been put on. It's not really anything to worry about, except that I'm going insane trying to cope. I know that some of my autistic/Aspie/auditory processing disordered friends have special earplugs that help to reduce background noise so you can focus on important things/people. Please tell me what these earplugs are called in as much detail as you can, and where you got them from, so I can either buy or order some!
I also need some blocking out of most sounds earplugs, to cope with travelling on buses or trains. Ideally these should reduce outside sounds without also increasing my ability to hear inside sounds, as I get panicky when I can hear nothing but my own heartbeat.