This isn't really a difference in pronunciation between Hindu and Urdu as much as it is a sound change that has occurred in some dialects of the Hindustani lang

This isn't really a difference in pronunciation between Hindu and Urdu as much as it is a sound change that has occurred in some dialects of the Hindustani language. Both Hindi and Urdu have the consonant /z/. However in parts of India this consonant has shifted from /z/ to /dʒ/. It is considered colloquial or uneducated.