sort of, but in my case, i mean what i saw, was written "I hadnt heard that" but nothing was followed with this.... i could understand it if: "I hadnt heard that before..."
The verbs "hear" and "see" work the same way in this respect.
"before" can be used to reinforce or clarify the idea of one event preceding another, but you don't have to append it when using the past perfect. "I hadn't heard that before" and "I hadn't heard that" are both possible.