Neal A. Maxwell taught that Joseph used a seer stone to translate plates in Ensign.

The Prophet Joseph alone knew the full process, and he was deliberately reluctant to describe details. We take passing notice of the words of David Whitmer, Joseph Knight, and Martin Harris, who were observers, not translators. David Whitmer indicated that as the Prophet used the divine instrumentalities provided to help him, “the hieroglyphics would appear, and also the translation in the English language … in bright luminous letters.” Then Joseph would read the words to Oliver (quoted in James H. Hart, “About the Book of Mormon,” Deseret Evening News, 25 Mar. 1884, 2). Martin Harris related of the seer stone: “Sentences would appear and were read by the Prophet and written by Martin” (quoted in Edward Stevenson, “One of the Three Witnesses: Incidents in the Life of Martin Harris,” Latter-day Saints’ Millennial Star, 6 Feb. 1882, 86–87). Joseph Knight made similar observations (see Dean Jessee, “Joseph Knight’s Recollection of Early Mormon History,” BYU Studies 17 [Autumn 1976]: 35).