What are called auditory hallucinations are usually considered a symptom of mental illness. Have you tried any medications?
While not common in the west, occult practices can sometimes open a door to this type of difficulty. There is a type of yoga that warns of encountering hostile entities.
If trying to tackle this on you own, you might see what condiditions make things worse and what conditions improve things. If you find activity like exercise makes things better, you might try to find ways to have more activity in your life. If something like meditation gives an improvement, you might explore ways to increase that.