Tinnitus hum, but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear. Rarely, pulsatile tinnitus may be a symptom of potentially life-threatening conditions such as carotid artery aneurysm or carotid artery dissection. Pulsatile tinnitus may also indicate vasculitis, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be an indication of idiopathic intracranial hypertension. Pulsatile tinnitus can be a symptom of intracranial vascular abnormalities and should be evaluated for "irregular noises of blood flow" (bruits). The mechanisms of subjective tinnitus are often obscure. While it is not surprising that direct trauma
Tinnitus masker tinnitus sounds and background sound. More advanced software based tinnitus maskers can use a combination of natural and synthetic sounds or a filtered noise generator tailored to mask the specific frequencies at which the tinnitus signal is experienced. Some sufferers require masking at all times. These people may employ wearable hearing aids which amplify ambient sound, generate low level wide band sounds such as white noise, or combination devices that mix both functions into one device. A standard hearing aid may be used for tinnitus masking; the tuning and amplification characteristics are different than when one is used in compensation