[. . . ] Large-diameter unit closed type headphones for powerful sound experience Use the two cords as required depending on the conditions. This feature reduces ambient noise (in-flight airframe noise, bus or other vehicular noise, indoor air-conditioner noise, etc. ) to 1/5th normal levels , allowing high-quality sound even in such ambient noises. As a result, the need to raise sound volume to excessive levels is reduced. [. . . ] As a result, the need to raise sound volume to excessive levels is reduced. 2 Insert batteries, taking care to align their and polarities correctly. 3 Power switch Provided with three positions: OFF, ON1 (noise canceller on), ON2 (noise canceller + SRS surround on) 4 VOLUME control dial Rotate to adjust sound volume. 5 Ear pads 3 Close the battery cover and slide back to its original position. When batteries become expended, the power indicator will become darker, and sound will appear distorted, with greater than normal amounts of noise. When the headphones are in continuous operation, nominal battery life will be as follows: AAA Alkaline batteries: About 20 hours AAA Manganese batteries: About 8 hours (Battery life may vary depending on surrounding temperatures and other conditions of use. 1 Press and slide open the battery cover on the left headphone cover as shown in the illustration. To protect your ears from damage, always rotate the volume dial of the headphones or your music device to its lowest position before wearing the headphones. 1 Attach one end of the furnished connection cord to the headphones, and the other end to your music playback device. When connecting the headphones to an airline onboard audio system, use the supplied plug adapter (the adapter may not comply with the systems used on some airlines). The problem may also be caused by factors other than the headphones themselves, so be sure to check the sound components with which the headphones are used. If the problem persists after making the following checks, consult your dealer or nearest Pioneer Service Station. If you are covering the microphone part of the headphone with your hand, remove your hand. Set the power switch to position ON1 or ON2 (power indicator lights green). Do not subject headphones to dropping, striking, or other severe impacts, since damage may result. To ensure high quality sound reproduction, keep the plug clean by wiping occasionally with a soft clean cloth. A dirty plug may cause degradation of sound quality or interruption of sound production. Avoid leaving the headphones in the following places: ­ Automobiles with closed windows, other locations exposed to direct sunlight, or nearby heating appliances or places exposed to high heat. When the sound volume is raised excessively, sound may leak and bother persons nearby; avoid excessive sound volumes. In locations exposed to high levels of noise, it is common to raise the sound volume to compensate for surrounding noise, but to ensure safety, the volume should not be raised so high that you cannot hear sounds of danger or warning. [. . . ] When the sound volume is raised excessively, sound may leak and bother persons nearby; avoid excessive sound volumes. In locations exposed to high levels of noise, it is common to raise the sound volume to compensate for surrounding noise, but to ensure safety, the volume should not be raised so high that you cannot hear sounds of danger or warning. The headphones' ear pad material may degrade or decompose after extended use or storage. In the event of severe soiling, dip a clean cloth in a weak solution of neutral detergent, wring the cloth, and wipe gently. [. . . ]