Laser (Tungara) Frog Synth

Before the sun had even set on my first day in Gamboa I had already heard excited chattering about the sound of the “Laser Frogs”. Once it got dark there was a seemingly ubiquitous chorus of these laser sounds, an asynchronous melange of descending glissandi. One might mistake this biophony for a retro video-game arcade, but it is in fact the revelry of an amphibious Bacchanalia.

Túngara Frog in a puddle, photo courtesy of Mangtronix
Chorus of Tungara frogs at night in Gamboa
Spectrogram of the frog chorus

First Attempt

I had other plans and project ideas before arriving at DINACON, but I found myself continuously drawn to the sound of these frogs. I was completely ignorant of them at first, having no idea what their actual name was or anything about their behavior or even what they looked like. I just really liked the way they sounded and kept listening. Indeed these frogs sound like a laser beam from a video game, and since I have worked as a sound designer and synthesized laser beam sounds for video games, I thought “I bet I can synthesize these frogs!”.

My first attempt was a very quick patch using the ES2 synthesizer in Logic Pro. I did this based entirely on listening to the frogs before analyzing the spectrogram in detail. It captured the general gesture of the descending tone, but didn’t capture the timbre or slope of the glissando very well.

ES2 Logic Pro Patch for Laser Frog Synthesis
Lazer Frog Synth attempt #1

Making the Whine

Although the first attempt was not convincing enough, it was close enough to encourage me to continue on my quest to synthesize the frogs call. I began by inspecting an isolated call from one frog via the spectrogram in Audacity.

Túngara frog recording with whine and three chucks
Spectrogram of Túngara frog recording with whine and three chucks

There are many noticeable things from this spectrogram that further inform what we hear. The first being that the frogs make not only this “laser” sound, but also have a percussive sound that follows it. At first I referred to these components as the “chirp” and “beep”, but after being clued in by some STRI researchers (thanks Amanda Savage!) I learned to use the terms “whine” and “chuck”. These are much better descriptions in my opinion.

I decided to use the SuperCollider programming language so that I had absolute control over the synthesis of this sound. The first area of focus was on creating a convincing “whine” using a bank of sine wave oscillators.

Looking at the spectrogram above we can see the “whine” portion of the call is a descending tone, starting around 1kHz and ending about an octave below. It also appears to have some harmonic overtones that decrease in intensity (up to about the 5th harmonic) Here is a recording and spectrogram of the first attempt in SuperCollider.

Túngara “whine” synthesized, first attempt in SuperCollider
Spectrogram of synthesized Túngara whine in SuperCollider

This was already sounding better, but by looking at the spectrogram of the synthetic whine some things are obviously still lacking. First, the slope of the glissando is still too linear, it needs to have more on a exponential (perhaps cubic?) curve to it. Additionally the upper harmonics are too strong and need to be attenuated relative to their ordinality. (The higher the harmonic, the less loud it is)

Making the Chuck

After a few more iterations of refining the whine, I moved onto the chuck.

Spectrogram of Túngara frog chucks.

Looking at the chucks in the above spectrogram we can see partials at relatively even spacing. We could perhaps model this by using a harmonic tone with a fundamental frequency of ~200 Hz or ~250 Hz, with the fundamental and first few overtones missing. The chucks seem to have their highest peak around 2.75 kHz. Is this sound produced via some sort of formant resonance? What mechanism makes it seemingly harmonic but with a missing fundamental? This is unclear to me, but I can recreate the sound nonetheless!

This group of three chucks have different durations, and the last one seems to have a downward pitch contour but not nearly as pronounced as the whine. The first two beeps are approximately 50 milliseconds long, and the third is 40ms.

Using the same approach as the whine, I used a bank of sine wave oscillators to recreate the chuck. Below is a recording and spectrogram along with the synthetic whine.

Synthetic whine and chuck of Túngara frog
Recording of synthetic whine and chuck of Túngara frog

While the timing of the chucks is accurate, the tone is not convincing. I continued to iterate on the implementation until settling on the one below.

SuperCollider GUI Application

For presentation at Dinalab I put together a simple GUI application which allows the user to playback a recording of an isolated Túngara call and compare it to the synthetic whine and chuck. Additionally there are knobs to alter the pitch of both the whine and chuck to hear what GIANT or tiny Túngara frog might sound like.

Video of Tungara Frog Synth SuperCollider GUI Application

Here is the audio of the final form the synthesizer took, there is still room for improvement of course.

Version 6 of Túngara frog synthesizer

Playback in the Field

In order to see if my synthesizer was effective at blending in with Túngara frogs in the field, I did some simple, not very well controlled tests on the streets of Gamboa.

Basically, I walked up to a pond where I heard Túngara frogs calling and they would usually stop calling as I approached. Then with my field recorder running I would play the synthesized call from my cell phone and wait to hear a response.

Here is the first trial (that loud percussive sound in the background is a Gladiator frog, I think) The synth is mostly in the left channel while the other frogs are mostly in the right.

Field test 1 of Túngara frog synthesizer

After shuffling around a bit, the frogs got quiet and I tried again.

Field test 2 of Túngara frog synthesizer

Now, can I conclusively say that the frogs responded to my call? I do not know, I am not a field biologist or experienced with phonotaxis studies, but the results of these simple tests seem promising. I think the frogs are buying my synthetic call.

Future Work

I really enjoyed working on this project and am very interested in improving the audio synthesis and application interface so that it is useful to researchers both in the field and the laboratory. If you study frogs, bioacoustics, phonotaxis or have interest in this project please get in touch with me, I would love more feedback.

From my perspective, the synthesis could still use some refinement. First, it could use better filtering of the whine, perhaps via a resonant filter based on accurate resonances of the frogs vocal apparatus? Additionally, more variability in chuck production would be useful. With more analysis of recordings and a bit more reading on the physiology of the chuck production I think I could better refine the synthesis.

Some final questions:

Perhaps I should port this synthesizer for use in a web/mobile app?

Maybe I could synthesize Gladiator (or other) frog calls?

What additional features would be useful?

Do you have comments, criticisms or any feedback?

Acknowledgments

First I would like to thank all the participants I met at Dinacon, and Dr. Andrew Quitmeyer for organizing the event.

Amanda Savage was very generous in talking with me about my project and in introducing me to the vast literature and research available on Túngara frogs.

References and Further Reading

Quick Guide – Túngara Frogs, Rachel A. Page and Ximena E. Bernal

The Túngara Frog: A Study in Sexual Selection and Communication, Michael J. Ryan

Complex Call Production in the Túngara Frog, M. Gridi-Papp

Unlucky túngaras

There are many, many more papers written about these frogs. They are certainly one of the most studied frogs in documented human history.

Rainforest Digital Memories

In Gamboa, I felt really astonished by the gorgeous nature that surrounded us.

My idea was to reveal what we don’t see to viewable data. Using the small movements of leaves and other nature elements moved by the wind to reveal itself.

The process I followed:

  • Record video footage of palms leaves moving, flowers, water…anything moved along the wind.
  • Select small loops and export them to a smaller resolution (1280×720) and best performance codec using ffmpeg :

/usr/local/bin/ffmpeg -i  originalvideopath.mov -s 1280×720 -b 1000k -ab 128k convertedvideopath.mp4

Rust Garden

Rust is gorgeous. We marvel at its endless shades of ochre, red, orange and sienna. We appreciate the organic shapes created as right angles collapse and edges decay into jagged landscapes. Rust is poetic, photogenic, artistic and melancholy. It grows on its own and famously, never sleeps.

As an agricultural species, we love to garden. We plant seeds outdoors, water them diligently, watch the miracle of life, trim, weed, and appreciate the lush green plantscape we’ve created. Gardening gets right at our souls. But why limit ourselves to plants?

Let’s garden with rust! Rust gardening is easy and the perfect way to exploit a “brown thumb.” In some ways it’s identical to growing a plant garden. In other ways it’s the polar opposite. A rust garden is created by “planting” metal pieces outdoors where they can weather organically. Patience is required, though the process can be sped up with regular watering, plus a few other tricks. You’ll eventually be rewarded with lush decay, in a myriad of sunset colors. Of course, your rusted wonder won’t bear anything edible, but it also won’t attract any pests. You might even extract a centerpiece-worthy “bouquet” from your rust garden, in leiu of a traditional harvest. Of course pesticides are unnecessary, and weeding is entirely optional.

For this year’s Dinacon I’m planting a rust garden outside of a home in Gamboa, Panama. Since I’ll only be there for two weeks, I’ve chosen to accelerate the initial rusting process using a household concoction of white vinegar, peroxide and table salt. The results are instant, but really just a head start on what promises to be a post-industrial patch of sepia-toned disintegration, offsetting the riot of tropical greenery.

Here’s how to make your own rust garden.

  1. Pick a patch of ground outdoors. You can also set up an indoor planter box or humidity-rich terrarium.
  2. Gather some scrap iron or steel. If it’s already rusting, so much the better.  Painted or coated metals won’t rust quickly. Strip the paint and sand the metal for best results. If you’re not sure a metal will rust, try it anyway. Experimentation is a terrific way to learn, and the artist’s favored tool.
  3. You can leave the metal to rust on its own outdoors, or water it regularly to accelerate the decay.
  4. If you’re an impatient gardener, it’s easy to get some rust going immediately. Pour some white vinegar into a plastic spray bottle and mist your metal scraps until they are thoroughly moistened. Wait for the vinegar to dry, around 15 minutes. Next, in another spray bottle, mix:
    • two cups of hydrogen peroxide
    • four tablespoons of white vinegar
    • one-and-a-half teaspoons of table salt (why salt?)
  5. Swirl the mixture until the salt has dissolved. Spray it onto your metal scraps and they will turn rusty as you watch. Allow the rusty metal to dry, then repeat as desired.* Careful with this mixture, it will rust anything it contacts instantly!

“Plant” other metal scraps as often as desired to create a variety of rusty delights. You can include non-ferrous metals like copper which will grow a green patina for contrast. Rust gardens are perfect for photography, try a macro lens for the most beautiful corrosion close-ups.

Rob Faludi

* Rust recipe inspired by Bob Vila.

Ruben Oya

Aug 26th – Sept 3rd. I’m an industrial designer from Barcelona. Focused on human interaction I’m experimenting with technology in form of wearables and installations. Let’s get inspired by the playful side of nature!

Michael Ang (Mang)

Dates: Aug 13-31

Project: Unnatural Language

During Dinacon I will create environment-specific sonifications using the Datapods (developed for Unnatural Language with Scott Kildall). Datapods are electronic devices that translate the unseen activity of plants and the environment into sounds for human appreciation. The troupe of Datapods will be spread into the jungle to converse with the environment, us, and each other. The Datapods are a modular system based on Arduino – curious to see if we can create new sensors and ways for them to interact with nature!

Michael Ang (https://michaelang.com) is a Berlin-based artist and engineer who creates light objects, interactive installations, and technological tools that expand the possibilities of human expression and connection. Applying a hacker’s aesthetic, he often repurposes existing technology to create human-centered experiences in public space and the open field. Countering the trend for technology to dissociate us from ourselves and surroundings, Michael’s works connect us to each other and the experience of the present moment.

Päivi Maunu

Dates: 21-31.8.2019

Project: Biomimeticx2 is creating a link between visual art and bioinformation on a site-specific project named the Cloud Garden in Panama.

The plan is to focus in a miniscule, 1 square meter area which will be called the Cloud Garden in Panama. The art work is a continuation of The Cloud Garden in Harakka island in Helsinki founded in 2015.

The project will transform into Community Art when we are kindly requesting other conference members to provide images from the milieu of conference e.g. via Google Drive.

Bio: Päivi Maunu is a visual artist living and working in Helsinki, Finland. She graduated as an environmental artist from Aalto University in 2011. Maunu is a multidisciplinary artist practicing Performental Art (a combination of Environmental Art and Performance Art), that she has established and advanced further since 2010.

She has participated in several international performance festivals such as Live Action Venice, Venice Biennale 2015, 2017 Preview Week and environmental conferences such as Digital Naturalist Conference in Thailand in 2018.

Päivi Maunu is a one of the founding members of art and research groups Nature&Art Post Scriptum (NAPS) and Biomimeticx2.

Mike Grusin

Hey everyone, I’m honored to be a part of Dinacon and will be joining you the first week of August. I’m hard to categorize; I’m an engineer and artist at heart and am happiest when I get to wear a lot of hats. I’ve built spacecraft and fighting robots, made costumes and movies, chased the shadows of asteroids and rare birds, and designed electronics for both the space station and just to make people laugh. I was most recently employed by Sparkfun Electronics, where I was an engineer with strong proclivities towards education and citizen science. I’m currently doing freelance design work for the Boulder CO aerospace community (will work for launch). At Dinacon I plan to serve as roving tech support; if you need electronics, coding, or media help, just let me know!

email: [email protected]
twitter: @flyingcircuits
insta: mikegrusin
site: flyingcircuits.com
whatsapp/SMS: +1 303 931 4219

Kitty made a comic

I’m learning how to use Procreate, and I thought I’d use it to flesh out an idea that’s been on my mind lately. I’m going to try to make a longer comic about yarncrafting during Dinacon!

-Kitty Kelly/WellReadPanda

Agouti Duties

So, Gamboa, home of Dinacon, is also home to these wonderful, adorable little rodents called agoutis – which bear some similarities to capybaras, but have been deemed infinitely superior for reasons I do not 100% understand. (Maybe because capybaras get all the press?)

I am here to document Dinacon but also am not very good at photos. Go figure.

Agoutis have pretty much become the mascot of Dinalab – Andy is always posting insta stories of their antics, the Dinatruck has an agouti decal, etc. – so of course they needed to have a pretty substantial presence here at Dinacon.

And they do – in the form of a series of Agouti-Do and Agouti-Don’t posters hung about the lab, reminding Dinasaurs of a few simple guidelines for being cool like an agouti (and not smug jerks like those capybaras).

Anyway, they are rad – great job, Andy! – so I thought I’d post a few of them:

So, to recap, just remember: At Dinacon or otherwise, it’s your duty to be cool like an agouti. Good luck out there!

P.S. This Dinalab poster doesn’t have anything to do with agoutis, but I still feel like it captures a lot of that Dinalab spirit.

Kris Casey – Beginning Endless Forms

August 12-19th. Kris Casey is a visual artist and creative researcher from Chicago, IL. Her work draws heavily from various fields of philosophical and scientific inquiry, including evolutionary developmental biology, bio-aesthetics, evolutionary aesthetics, and genetics. Her research and practice examines relationships between biology and technology, natural and artificial, material and immaterial, subject and object. Her paintings can be seen as assemblages or accumulations of natural and technological elements whereby the biological concepts of mutation, contamination, decay, generation, emergence and metamorphosis become modes of inquiry into the production of novel forms.