Tinnitus is only in the brain, not in the ears. It's a perpetual loop - the brain listens for the sound; creates the sound so it can listen for it'; which stimulates it to create it. On and on. Yes there are things that make it worse - my experience is NSAIDS and anti-histamines turn a few cicada songs into a full blown orchestral suite of ringing, clanging, whooping. I imagine these holds work - if they do- because you're concentrating on doing something other than listening for the noise in your head, and so your head reduces the noise it makes for it to listen to.