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 in 90% of persons but in rare cases, an hour or more. The period of complete silence is usually seconds to about a minute. If the trigger sound is repeated at intervals, tinnitus can be suppressed as long as the repetition lasts. The residual inhibition (RI) effect first noted in 1903: the capacity of a sound of the right frequency and intensity to briefly attenuate or suppress tinnitus. To distinguish the tailored sound used for inhibition from the broadband undifferentiated sound employed in tinnitus maskers, it is usually referred to as the 'trigger' or 'quieting' sound. The trigger sound is