The Leslie, named after its inventor, Don Leslie,6.9 is a popular audio processor used with electronic organs and other instruments [59,190]. It employs a rotating horn and rotating speaker port to ``choralize'' the sound. Since the horn rotates within a cabinet, the listener hears multiple reflections at different Doppler shifts, giving a kind of chorus effect. Additionally, the Leslie amplifier distorts at high volumes, producing a pleasing ``growl'' highly prized by keyboard players. At the time of this writing, there is a nice Leslie Wikipedia page, including a stereo sound-example link under the first picture (that is best heard in headphones). Papers on computational audio models of the Leslie include [470,192].
The Leslie consists primarily of a rotating horn and a rotating speaker port inside a wooden cabinet enclosure .