There is a very handy list with contexts at: http://www.lancsngfl.ac.uk/curriculum/literacy/lit_site/lit_sites/phonemes_001/
This Powerpoint presentation includes the sounds:...
Voiced means spoken using a vibration of the vocal cords. Sometimes, whether consonants are voiced or voiceless depends on the word.
In " This Thursday." for example, the th in 'this' is voiced,...