Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 436)

3.
In the single-image display, tap < > or press < >.
4.
Press < > to play back the movie.
(1) Speaker
The movie will start playing back.
You can pause playback and display the movie playback panel by
pressing <
>. Press it again to resume the playback.
Turn the < > dial to adjust the volume (even during playback).
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