What 08_15 said.
I would like to add that the first "d" is sometimes not pronounced at all, some people would say something like "sköllpadda" :-D
(I just asked my husband, who says "sköllpadda" and a friend who wants to keep the "d", so both would be OK, even though the voice here pronounces it a lot more distinctly than most people would) :-D
What language should 'holdpadda' be pronounced in? If it's supposed to be Swedish, the answer is no.
The SK-sound in sköldpadda is the same (or similar) sound as the CH sound in LOCH NESS.
The robovoice pronounces it correctly, but if you just want to listen to just that one word, then see here: http://www.forvo.com/word/sk%C3%B6ldpadda/#sv