In more than 5,000 of his speeches, Adolf Hitler dazzled audiences with his famously powerful and hysterical speaking style. The Führer’s voice and presence is universally described by his biographers as spellbinding, mesmerizing, and charismatic.

Above all, the Nazi leader’s booming voice is associated with his famous oratory. But Hitler’s normal speaking voice remained largely unknown outside of his innermost circle.

In 1942, a Finnish sound engineer recorded 11 minutes of an informal conversation between Adolf Hitler and Gustaf Mannerheim, commander-in-chief of the Finnish Defence Forces. To this day, it remains the only known recording of Hitler’s normal speaking voice.