For the direct pronouns, the unstressed pronoun us = ci.
The stressed pronoun us = noi
For the indirect pronouns, the unstressed pronoun to/for us = ci.
The stressed pronoun to/for us = a noi
I don't know where ce comes from so I can't tell the difference, but as far as I know it isn't a part of the pronouns.
When indirect object pronouns are used with any direct object pronoun in one of these sequences:
- indirect direct verb
the indirect object pronouns change:
- mi => me
- ti => te
- gli => glie
- le => glie
- si => se
- ci => ce
- vi => ve
I hear "chi vee" clearly and faintly "dono", so I recommend that your volume be all the way up if you don't have it at full volume. Alternately, I recommend listening at this site to native speakers: http://forvo.com/search/ci%20vedono/ Amusingly, the recording of "vedono" seems to also lack its ending. The google translate recording seems to have a problem with this word. Oh, try this one: http://www.acapela-group.com/
The "ch" sound is very clear when I listen to it, rather than "sh". However, with your ears not being accustomed to Italian, your brain is trying to translate it into the nearest English that it can. You may be expecting a long vowel sound where she uses a short vowel o. I hear (chee veeduhno) with stongest stress on first syllable "ve" of "vedono" and second strongest on "ci" and third less strong on "no" of "vedono", while "do" is an unstressed syllable according to Duolingo. Try listening here at Forvo for some sentences: http://forvo.com/search/ci%20vedono/it/ Oh dear, we need an Italian user to add another sound bite there. They have "ci vediamo" pretty clearly and then "vedono" without the last syllable at all!