Doctrine and Covenants, Section 6, discusses many things that are wise and prudent to consider regarding following the counsel of the Lord in our lives and receiving answers to prayers.  At the end, though, we find Christ telling Joseph Smith and Oliver Cowdery:

“Behold the wounds which pierced my side, and also the prints of the nails in my hands and feet; be faithful, keep my commandments, and ye shall inherit the kingdom of heaven.”

If the Savior was directing them to “behold” the marks of the crucifixion, I suspect that they were indeed able to do so.  This evidences, in my mind, that this revelation wasn’t delivered in a still small voice, but at least included a portion of which where Joseph and Oliver were able to behold what the Lord directed them to behold.