Board Thread:Questions and Answers/@comment-11255996-20130721105715/@comment-948616-20131116090202

according to what sources I can find (oddly enough a sample NOT on this wikia) "Ben's voice remained the same though sounding more computerized. This is due to Galvanic Mechomorphs being unable to bond with living organisms, thus Ben's transformation into Upgrade is incomplete"

yeah it's taken from wikipedia.