DINOSAUR SOUNDS
NAVIGATION
We will never know the range of sounds produced by dinosaurs - who could predict the variety of bird songs by just looking at a bird? Well, actually a dead bird. That has been buried in mud. And has been squashed underground for more 65 million years so that the mud turns to rock.
We can get some indication for some animals however! The duck-billed Parasaurolophus lived in North America and Canada in the Upper Cretaceous Period (76 to 65 million years ago). It famously had a large, hollow crest on its head which was composed of a number of hollow tubes that behaved something like an organ pipe.
ACTIVITY
Making and analysing a parasaurolophus crest
This activity is an experimental investigation into the possible sound of an extinct animal. It brings together a number of aspects of biology, physics and electronics and makes use of quantitative analysis using and rearranging several simple mathematical formula. It includes:
- Consideration of the anatomy of the crest and construction of a bio-simulation from simple and easily obtainable materials.
- Discussion and simulation
(using multi-media) of the science of how sound waves behave
in such a pipe and analysis of them with some simple formula.
- Design, analysis and building of a simple electronic circuit to act a vocal cords.
Testing
We've built our crest, analysed the science and constructed the electronics - now it's time to test it!
Attach a small speaker to the inlet and turn the circuit on. Note, the demonstration works best if the speaker has the same diameter as the pipe and is securely attached. Adjust the frequency by changing the tuning resistor. As the frequency hits the resonant frequency of the pipe, the sound will get noticeably louder. You may have to experiment with the volume of the speaker to get the best effect.
Now you know what frequency to aim for try playing the crest by vibrating your lips at the inlet. Note how you can get a much wider range of sounds when using your lips than was achieved by using the electronic circuit. This would be more indicative of the real call if parasaurolophus had vocal cords.
Contact:
Tel: 01663 749785
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