Acoustic Shadow (sometimes called Silent Battle) is a strange thing. It is a phenomenon where sound is unheard close to the cause of the sound, but the same sound is heard a far distance away from its source. With a unique combination of factors such as wind, weather, temperature, land topography, forest or other vegetation, and elevation, battle sounds are not heard at a distance they normally would clearly be heard.

The distance the sound is heard may be great, even hundreds of miles, yet nearby (sometimes mere miles away), the sounds are not heard. Battles where the Acoustic Shadow phenomenon occurred in the Civil War are Gettysburg, Seven Pines, Iuka, Fort Donelson, Five Forks, Perryville, and Chancellorsville.

Acoustic Shadow could have a profound effect on a battle. During the Civil War, it was common for armies to be spread out over large distances and timely communication between the split parts of an army was crucial to battlefield success. Army commanders must make decisions based on current knowledge of the situation before them. The sound of a battle would be a form of communication, signaling to a Civil War commander and his staff where a battle is taking place, and what troops (including enemy) may be involved. If Acoustic Shadow hides battle action from being heard by a commander, then communication has been lost and dire consequences may follow as the commander does not respond as needed to the battlefield situation.

Examples of Acoustic Shadow During Civil War Battles:

  • Battle of Gaines’s Mill – More than 91,000 men were engaged in battle at Gaines’s Mill, Virginia on June 27, 1862. Confederate commanders and troops were less than two miles from the battlefield and could plainly see the smoke and flashes from the guns and artillery, but not a sound could be heard of the battle for two hours. Strangely, the battle sounds from the Battle of Gaines’s Mill were easily heard in Staunton, Virginia over one hundred miles away.
  • Five Forks – Fives Forks was fought from March 30 to April 1, 1865 and was part of the Appomattox Campaign. Confederate Generals George Pickett and Fitzhugh Lee were enjoying a shad bake with other generals north of Hatcher’s Run when the battle of Five Forks began a short distance away. Because of Acoustic Shadow, Pickett and Fitzhugh Lee were unaware a fight was under way. Pickett finally responded, but arrived late for the battle. Pickett and Fitzhugh Lee have been criticized by Civil War historians (please see Lee’s Lieutenants, III, 665-670) for not acting on “the dread immediacy of the crisis” (ibid., 665) at Five Forks.
  • The Battle of Gettysburg – The battle sounds from Gettysburg fought on July 1, 2, and 3, 1863 could be heard over one hundred miles away in Pittsburgh, but were not heard only ten miles from the battlefield.