I am sorry that your question was unanswered for long.
Investigations done for the tinnitus are;
1) Audiometric evaluation
2) A complete blood cell count, an autoimmune panel (ANA, sedimentation rate, rheumatoid factor), and thyroid function tests.
3) MRI of the brain and internal auditory canals.
4) MR angiographic scanning; in this a dye is injected and looks at the blood vessels of the brain (as defects in them may be causative for this sound).
Treatment for tinnitus includes correcting identified comorbidities, as well as directly addressing the effects of tinnitus on quality of life.
1) supplementation with vitamin A, vitamin C, cyanocobalamin, and nicotinic acid, or with magnesium, zinc, or copper.
2) clonazepam 0.5 mg at bedtime has been suggested. Another suggested medication has been alprazolam.
3) Tinnitus masking; Many people do not notice tinnitus if there is some background noise in the room.
a) may turn an FM radio
b) opt to purchase sound generators (like producing the sound of ocean waves).
c) specific tinnitus-masking devices are also marketed.
4) Tinnitus retraining therapy (TRT) involves retraining the subconscious part of the auditory system to accept the sounds associated with tinnitus as normal, natural sounds rather than annoying sounds. The goal is for the person to become unaware of their tinnitus.
5) Biofeedback and stress reduction - Biofeedback is a relaxation technique that teaches a person to control certain body functions, such as heart and breathing rate. Biofeedback may help to manage tinnitus-related distress by changing their reaction to it. One may experience relief of tinnitus symptoms once they are able to stop thinking of their tinnitus as bothersome or stressful.
6) Herbal remedies - Combinations of herbs (also called botanicals) Ginkgo biloba and melatonin are suppose to be slightly beneficial in treating tinnitus.
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.