Rather than hearing the trumpet call ahead of Armistice Day on Sunday, some heard what appeared to be crowd noise, with those at the ground insisting silence had been observed.
Sky has put the problem down to a "technical error".
A statement read: "We are aware that some viewers experienced audio issues during the playing of the Last Post prior to the Sheffield derby, we apologise unreservedly for this regrettable technical error."
The game at Bramall Lane ended 0-0, with Sheffield Wednesday goalkeeper Cameron Dawson saved a penalty from Sheffield United's David McGoldrick in the 15th minute.