Wot they all said. With luck it’ll go away today. If it doesn’t you’re probably stuck with it. I was told it’s agravated by caffeine, red wine, tonic, citrus fruit. I’ve cut out the caffeine but would prefer not to live a life without fruit or wine.
On the plus side I’m lucky enough to associate it with the pleasant feeling of being dead tired. It doesn’t annoy me, it just gets in the way of hearing stuff.
Ebay for a big pile of different earplugs – find one you like. My favourite are MAX LITE SNR34 in flouro green.