2008 GMC Sierra 1500 Pickup Owner's Manual - Page 246

Headphones Push the power button to turn on the headphones. An indicator light located on the headphones comes on. If the light comes on but, there is intermittent sound and/or static on the headphones, or if the indicator light does not come on, the batteries might need to be replaced. See "Battery Replacement" later in this section for more information. Switch the headphones to Off when not in use. Infrared transmitters are located at the rear of the RSE overhead console. The headphones shut off automatically to save the battery power if the RSE system and RSA are shut off or if the headphones are out of range of the transmitters for more than three minutes. If you move too far forward or step out of the vehicle, the headphones lose the audio signal. The headphones automatically turn off after four hours of continuous use. To adjust the volume on the headphones, use the volume control located on the right side. For optimal audio performance, the headphones must be worn correctly. The symbol L (Left) appears on the upper left side, above the ear pad and should be positioned on the left ear. The symbol R (Right) appears on the upper right side, above the ear pad and should be positioned on the right ear. The RSE includes two 2-channel wireless headphones that are dedicated to this system. Channel 1 is dedicated to the DVD player, while Channel 2 is dedicated to RSA selections. These headphones can be used to listen to the radio, CDs, DVDs, MP3s, DVDAs, any auxiliary source connected to A/V jacks, or the auxiliary input jack, if your vehicle has this feature. The wireless headphones have an On/Off button, channel 1/2 switch, and a volume control. 3-110