I recently had my home remodeled the plumbers removed cast iron plumbing and replaced with ABS pipe. I was told that sound buffer should be installed between floors my plumbers when using ABS pipe and that this would pretty much eliminate any noise transfer, is this true?

I recently had my home remodeled the plumbers removed cast iron plumbing and replaced with ABS pipe. I was told that sound buffer should be installed between floors my plumbers when using ABS pipe and that this would pretty much eliminate any noise transfer, is this true?
Please explain, in detail, the "sound buffer" you're referring to. Can you describe what itlooks like or better yet give us a picture. Short of wrapping the ABS stacks in insulation I don't see how any noise can be eliminated. But a lotta new stuff has come out since I retired. Educate me! Regards, Tom