I keep running into this confusion. An account manager refers to me as “that nice VOC lady.” (He’s partly right.) Another product manager wants to know why we have to have “so many people” participate in a research study (“you could just get a guy and ask him what he thinks!”) So it seems worth talking about the difference between the two, and why they’re both important. Because as much as I might hate to admit it, getting that punchlist from your Big Fricking Order customer is as critical to your business as ensuring a highly usable software UI.
I put together this chart of differences for a quick rundown of the differences. The biggest one to my mind is that VOC measures desires, while user research measures behavior. . The people (or personas) who participate are different, too: VOC is voice of the customer, but not necessarily of the user, whereas user research doesn’t necessarily include anything about the organization’s goals, or why the product is purchased.
I made a PDF, too.