Lowering your blood pressure (BP) may be as easy as shutting the window or turning down your MP3 player. Too much noise exposure correlates with a steady rise in blood pressure. Loud sounds are known to stimulate the pituitary-adrenal cortical system. Heart rate basically soars in response to sudden loud sounds, like slamming doors or honking horns. But a gradual rise in noise hurts, too. In a study of assembly plant workers, the higher the volume got, the higher their blood pressure rose. Simple earplug use was enough to drop systolic blood pressure as much as 5.5 mm Hg. So just imagine what turning down your car stereo could do.