Avian syrinx revisited
Synthetic birds have been done quite a bit, by Tamara Smyth (pressure impedance), Seppo Fagerlund (a three port waveguide) and Hans Mikelson ( a csound FM version ) [BTW if anybody else has got published models I don't of please let me know.]
http://ccrma.stanford.edu/~tamara/publications/ http://www.acoustics.hut.fi/research/avesound/pubs/akusem04.pdf http://www.csounds.com/ezine/winter2000/realtime/
I first put a tutorial on the syrinx up on my site 2 years ago after copying Hans FM/AM version from Csound to Pd and then messed with waveguide models and adding different beaks and trachea with some success.
http://www.obiwannabe.co.uk/tutorials/html/tutorial_birds.html
But the one thing kept evading me, squawking birds. Oscines are singing birds with a highly developed syrinx, and those are the ones everybody studies and tries to emulate. Turns out oscines are the easier ones to create. But "working class birds", crows, pigeons, ducks and seagulls are a different problem. I live by the sea and when they're not stealing my chips, seagulls fly by my room taunting me saying "come on then.. make a seagull sound!", but I could never work it out. Seagulls 1: Andy 0
Well I fixed that, I think. Thanks to some papers by these chaps, Suthers, Fee and Fletcher it was time to have another look at the syrinx.
http://www.indiana.edu/~songbird/pubs/publications_index.html http://web.mit.edu/fee/Public/Publications/Fee_etal1998.pdf
Starting with Tamaras pressure analysis again I decided to start making each bronchus separately as a pulse source then feed an FM stage with feedback. I guess this is the same as using FM with a complex modulator, but the feedback gets a semi chaotic effect which is what Fletcher suggests is behind the squawk of birds with bigger lungs and smaller syrinx.
Here's the results (with background to situate them - all synthetic scenery as usual)
First the regular oscines in a forest (with some recent insects) http://www.obiwannabe.co.uk/sounds/effect-rainforestbirds.mp3
Now two examples from the new model The star of this one is the duck... http://www.obiwannabe.co.uk/sounds/effect-riverbirds.mp3
And here's the seagulls (gotchya you feathered freaks!) http://www.obiwannabe.co.uk/sounds/effect-seabirds.mp3
The same model can do both, so it's quite flexible. All (pure) Puredata The Pd code is still a little messy to release but it will be on the site soon or in the book maybe.
Andy