Ps. At the end of the cable, near the scart plug, it also has an additional wire sticking out, ending with two audio plugs of the regular kind. Is there any sound coming through the video port anyways? Seems weird. Tried to put the cables into the red/white audio input on my tv after switching on the power, but only got a weird sound that got louder and louder, even if I turned off the power from the Amiga.
Seems more likely those audio connectors should go into the Amiga. The Amiga video port does not carry audio (afaik), but the SCART connector does.