[. . . ] Place the "L" earpiece in your left ear and the "R" earpiece in your right ear for proper fit and best sound. [. . . ] Connect the headphone plug to the headphone jack of your music player. If the plug is not fully inserted you may only hear sound from one earpiece. To protect your hearing, always start listening with the In-Line Volume Control set to a low level and gradually increase the volume to a comfortable listening level. For your safety, do not use headphones if they would prevent you from hearing warning sounds, such as while driving a car or motorcycle, riding a bike, etc. NOTE: In extremely cold or dry air conditions you may notice a slight `tingling' feeling in your ears when using in-ear headphones. This is the result of the build-up of static electricity in your body. [. . . ] This is the result of the build-up of static electricity in your body. [. . . ]