The whiskey is matured using the signature sounds of a custom-built motorcycle-specifically a 1941 Harley-Davidson EL Knucklehead.Mechanism: A waterproof speaker is submerged inside the barrel, playing the engine's revving sounds.Effect: The vibrations from the sound waves force the liquid in and out of the barrel's #3 char oak wood.Result: This accelerated interaction intensifies the smooth character and adds complex notes of vanilla, butterscotch, and spice.