[. . . ] The noise canceling circuit actually senses outside noise with built-in microphones and sends an equal-but-opposite canceling signal to the headphones. Note The supplied battery was included in the package during manufacturing (as a convenience to the user), it is possible that the battery life may be depleted by the time of purchase. The actual life of the supplied battery may be shorter than the standard time described in this manual when using a fresh battery. [. . . ] Tactile dot (on the left) Notes on the noise canceling function ˋ Adjust the earpads so that they cover your ears, otherwise noise canceling will not function properly. ˋ The noise canceling effect may vary depending on how you wear the headphones. Troubleshooting No sound ˋ Check the connection of the headphones and the equipment. When the battery is low Replace the battery with a new one when the POWER indicator blinks or lights off. Notes 2 Installing a battery Push ˎ The sound and noise canceling effect may become intermittent when the battery is low. ˎ The headphones will automatically switch to passive mode when the battery power is empty. The noise canceling effect is not sufficient ˋ The noise canceling function is effective in low frequency ranges such as airplanes, trains, or offices (near air-conditioning, etc. ) and is not as effective for higher frequencies, such as human voices. Quick folding style Original compact folding mechanism for easy carriage and storage. ˋ Producing balanced, clear and powerful high quality sound 300 kJ/m3 Neodymium magnet delivers powerful sound and equalizer provides balanced sound from bass to high note. ˋ Able to use as a regular headphones even when the POWER switch is set to “OFF”. 5 Wearing After use Notes on handling ˋ Because the headphones are designed to fit closely in your ears, forcing them against your ears may result in eardrum damage. Avoid using the headphones where they are liable to be struck by people or other objects, such as a ball, etc. ˋ Pressing the headphones against your ears may produce a diaphragm click sound. ˋ Be sure to consult a Sony dealer when the earpads become dirty or damaged, or when the headphones require repair work. ˋ Do not leave the headphones in a location subject to direct sunlight, heat or moisture. [. . . ] ˋ Be sure to consult a Sony dealer when the earpads become dirty or damaged, or when the headphones require repair work. ˋ Do not leave the headphones in a location subject to direct sunlight, heat or moisture. ˋ If you feel drowsy or sick while using this headphones, stop use immediately. [. . . ]