Creating the sound of a “Thumper”, the device the Fremen use to distract or lure the Worms, was one of the many core sounds Theo Green and I were tasked to create early in the design process.
A self powered mechanical device, the Thumper is plunged into the sand and pounds the surface of the desert, perhaps like a portable pile driver, creating rhythmic subterranean vibrations that attract (or distract) the Worms.
Knowing we needed a great deal of authentic sounds from the desert for so many other sounds in the film, Theo Green, Charlie Campagna, Eric Basta and I set out to the Mojave desert in California to capture as many acoustic and organic elements as possible for the film including elements for the “Thumper”.
Theo had already done experiments during a previous recording trip in the desert, capturing sounds of the “singing” sand dunes; a bizarre geological artifact of humidity, temperature, wind and sand granule composition that sounds tonal and almost alive. He captured them by burying hydrophones (microphones designed for recording under-water) in the sand to capture what is a very resonant body mass making those signature moans and groans. The discovery that desert sand could be resonant and transmit audio for several hundred yards and boom like a drum was a revelation.
We would, upon our return to the desert, bury hydrophones not far under the surface, maybe two feet, and pound the it with hammers and mallets to capture raw elements for the Thumper. This produced an extraordinary type of resonant impact that was both sandy and earthy yet booming and thumpy. The sounds you hear in the film of the Thumper pounding the sand are almost exactly what we captured in the desert with only a small amount of bass enhancement, using the subwoofer to add size.
The mechanics of the Thumper are made from other organic recordings of egg timers, plastic ratchets and hydraulic door closers. The on-camera Thumper was a practical prop that had a unique sound of its own and is part of the final sound of the device.
