Pontiac Montana SV6 2007 Owner's Manual page 310

If there is a decreased audio signal during CD,
MP3, or DVD play, there may be a low hissing noise
through the speakers and/or headphones. If the
hissing sound in the wireless headphones seems
excessive, make sure that the headphone batteries
are fully charged. Some amount of hissing is
normal.
Both sets of rear seat headphones may include
foam ear pads that can be replaced.
Foam ear pads on these headphones may
become worn or damaged. The headphone foam
ear pads can become damaged if they are not
handled or stored properly. If the foam ear pads do
become damaged or worn out, the pads can be
replaced separately from the headphone set.
It is not necessary to replace the complete
headphone set.
The headphone replacement foam ear pads can
be ordered in pairs. See your dealer for more
information.
310
Battery Replacement
To change the batteries, do the following:
1. Loosen the screw on the battery compartment
door located on the left side of the headphone
earpiece.
2. Replace the two batteries in the compartment.
Make sure that they are installed correctly
using the diagram on the inside of the battery
compartment.
3. Tighten the screw on the battery
compartment door.
If the headphones are to be stored for a long
period of time, remove the batteries, and keep
them in a cool, dry place.
Wired Headphones
There is a right and left wired headphone jack.
To adjust the volume, do the following:
1. Plug the headphone into the corresponding
jack, located behind the video screen, next
to the auxiliary jacks.