Non-sounding, nonaspirated : च (ca)
Non-sounding, aspirated: छ (cha)
Sounding, non-aspirated: ज (ja)
Sounding, aspirated: झ (jha)
Nasal (which will be discussed elsewhere)
These sounds are produced between the palate (the roof of the mouth) and the body of the tongue (in contrast to the retroflex sounds which are produced with the tip of tongue).
Tips for practicing the pronunciation:
– Test the aspiration with the palm of your hand. For non-aspirated sounds there should be no aspiration whatsoever. And for aspirated sounds the outbreath should be felt distinctly on the pal of your hand.
– Make sure that the aspirated sounding consonant is really sounding!