Number, in millions, of Americans who in the 1990s were persistently plagued by tinnitus (from the Latin tinnire, ”to ring“): a ringing in the ears or perception of sound where none is present


Americans, in millions, for whom tinnitus is a chronic problem now; while there is no known cure, common treatments include hearing aids (which help cancel out the ringing by clarifying other sounds) and other devices that create ambient noise


Common causes of tinnitus, some of which (hearing loss, consistent exposure to loud noise, and head or neck trauma) cause chronic tinnitus and others (certain medications, even wax buildup) just fleeting discomfort


Americans, in millions, who are temporary or chronic sufferers


Medications, most commonly aspirin and Alka-Seltzer, that include tinnitus as a potential side effect


Main types of tinnitus: tonal (a continuous ringing) and pulsatile (a rhythmic pulsing, often in concert with one’s heartbeat)


American veterans in 2010 who received disability payments for tinnitus caused by head or neck trauma, or by such battlefield noises as grenades, helicopters and gunfire


Number, in billions of dollars, paid to veterans for tinnitus disability in 2009


Number, in millions of dollars, allocated to tinnitus research in 2009