A lot of different things can cause it, blood pressure issues, stress, medication side effects, significant hearing loss, etc. If it is intermittent, it's usually not hearing loss related. One of the reasons it's difficult to fix is because it's really not your ears but your brain that is doing it. If it's hearing loss related, aids will sometimes help because some studies have shown the brain is wanting to fill that area where the loss is significant and when you wear the aids it is addressing the loss area but in the case of Justa if you have completely lost your hearing in one or both ears an aid can't correct that just like glasses can't help someone who is blind. A CROS aid is for someone who has single sided deafness and you wear an aid in the good ear and a receiver in the deaf ear and you are just feeding all sound into the better ear but that is just going to help with letting you being able to hear sound from all directions, it won't do a thing for tinnitus. A lot of aids like Oticon brand have a tinnitus therapy built in and there are maskers too but all they are doing is giving you a mild white noise to focus on so you try to ignore the tinnitus. Honestly, it is very rarely cured.