This video is dual sound. To watch with only one audio track, follow the directions here:
http://www.techulator.com/resources/3128-How-adjust-balance-between-left-right.aspx

Turn off one of the speakers by turning the volume down to zero.
The "R" Speaker is for ENGLISH.

Alternatively plug in ONLY ONE SPEAKER to listen to only one audio track.

Plug in the RIGHT SPEAKER for English audio.