An ultrasound is another test that may be used to aid in the diagnosis of tinnitus. An ultrasound uses reflected high-frequency sound waves and their echoes to create images of structures within the body. An ultrasound can reveal how blood flows within vessels, but is only useful for accessible vessels. It is not helpful for blood vessels within the skull.

Individuals with tinnitus describe perceiving a wide variety of sounds including ringing, clicking, hissing, humming, chirping, buzzing, whistling, whooshing, roaring, and/or whirling. These sounds may be present at all times, or they may come and go. The volume, pitch or quality of tinnitus sounds can fluctuate as well. Some people report that their tinnitus is most obvious when outside sounds are low (i.e. during the night). Other individuals describe their tinnitus as loud even in the presence of external sounds or noise, and some describe it as exacerbated by sounds. Tinnitus can affect one ear or both ears. It can also sound like it is inside the head and not in the ears at all.
If the source of the problem remains unclear, you may be sent to an otologist or an otolaryngologist (both ear specialists) or an audiologist (a hearing specialist) for hearing and nerve tests. As part of your examination, you may be given a hearing test called an audiogram. An imaging technique, such as an MRI or a CT scan, may also be recommended to reveal any structural problem.
Atherosclerosis. With age and buildup of cholesterol and other deposits, major blood vessels close to your middle and inner ear lose some of their elasticity — the ability to flex or expand slightly with each heartbeat. That causes blood flow to become more forceful, making it easier for your ear to detect the beats. You can generally hear this type of tinnitus in both ears.