Echoes from 65.5 Million Years Ago: Simulating the Sound of a Dinosaur with SigmaDSP

In the 1993 film, Jurassic Park, fictional technology helped recreate long-extinct dinosaurs. It gave us a thrilling sense of what these animals looked and acted like. What if real-life technology could be used in a similar way to recreate what a dinosaur might have sounded like millions of years ago?

(Please log in to listen) Turn your sound on & click play, to hear the dinosaur sound effects.

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The Parasaurolophus was a kind of hadrosaurid dinosaur default to North American during the Late Cretaceous period. Likely they traveled in herds for protection from predators, walking as easily on two legs as on four. Yet what’s most distinctive about a Parasaurolophus is its large hollow head crest. Of all the uses these wonderful creatures might have had for their crests, one of particular interest to sound engineers is their possible function as resonating chambers for vocalization. Imagine the racket a Parasaurolophus herd could make! But we can do more than just imagine it. Paleontologists at Sandia National Laboratory have simulated the sound, starting with a CAT scan of a fossil crest – see

http://www.sandia.gov/media/dinosaur.htm

Unlike the dinosaur cloning in Jurassic Park, recreating the sound of this crested reptile is one experiment that doesn’t need the usual warning of, don’t try this at home! Though ADI’s SigmaDSP chips are primarily for audio post-processing, there’s nothing to keep us from creating sounds with them. GUI programming via SigmaStudio, offering many analog-style processing blocks, makes this incredibly easy. Let’s start by placing feedback around a delay to make an oscillator:

Analog versions of circuits like this start up by themselves, except when they don’t. But with the mathematical-quiet of DSP, there’s nothing to get this oscillation going – so we need to provide a noise source. We can also add a compressor and/or a cubic clipper to help regulate the oscillation’s ultimate level:

Here, a white noise source starts up the oscillation – and perhaps unsurprisingly, this thing sounds much like blowing air across the mouth of a beer bottle. Not a very convincing animal sound, so we need to do better.

The head of our Parasaurolophus measures about five feet including the crest. It’s conceivable that a sound wave could make a ten-foot round trip inside this path— a delay of just over 10 mS. There could also be competing reflections around curves, so I included two more resonant tanks of shorter delay. Finally, we simply don’t know what vocalization the animal might make – so I assumed a trumpet-like series of harmonics to power the resonant chambers. The resulting schematic appears below:

What does it sound like? With this project running on a ADAU1452MINIZ eval board, playing with the Honk switch produced sounds we can capture with the Audacity sound recorder:

To hear the results, click on the Parasaurolophus image at the top of this post. There are two versions. The second one was made with different parameters and added “outdoor” ambient sound. Close your eyes and listen—and feel like you’ve traveled back 65 million years.

Even if creating an actual dinosaur remains science fiction, it’s easy and fun to produce “analog” dinosaur sound effects with SigmaStudio – making very old sounds with very new technology!