sonic deception
... that during World War II, the U.S. Ghost Army used sonic deception to confuse the Germans?
... that during World War<span id="mwAao" typeof="mw:Entity"> </span>II, the U.S. <a href="./Ghost_Army" id="mwAas" rel="mw:WikiLink" title="Ghost Army">Ghost Army</a> used <b id="mwAaw"><a href="./Sonic_deception" id="mwAa0" rel="mw:WikiLink" title="Sonic deception">sonic deception</a></b> to confuse the Germans?