Nikon 1 J3 Reference Manual page 108

Adjust display times and choose a background track.
2
Adjust the following options:
Frame interval Choose how long each still image is displayed.
Movie playback
time
Audio
I
88
Choose how much of each movie is played back
before the next slide is displayed. Choose Same as
frame interval to display the next slide after the
time selected for Frame interval, No limit to play
back the entire movie before displaying the next
slide.
Mute audio playback or
choose a slide show back-
ground track (to play the
highlighted background
track prior to selection,
press 2 and rotate the
multi selector to adjust
volume; to end playback,
press 2 again). Select
Movie sound tracks to play only audio recorded
with movies; in this case, no sound is played for still
images or Motion Snapshots.