What is this? It’s whale song, obviously! Not so obvious? Ok, let’s take a step back. You’ve heard whale song, no doubt. Either in the context of movies, a cheesy movement a decade ago of adding clips of them to pop and rock songs, wildlife documentaries, and so forth. It’s lovely and mysterious, and -new age poppycock aside- really quite captivating. There are a lot of scientific questions about whale song too. Are these noises random? Is there content? How much content? How individual-whale-specific is a whale song? If there’s information, is it wisdom of the ancients, directiions to food, or just gossip about whale celebrities?
All questions you’ve asked yourself too, I don’t doubt.
Well, some of our best minds are on the job, you’ll be pleased to know. One of them, Mark Fischer, is taking a new approach to the problem, with rather beautiful results. He is using a wavelet transform (Amara’s wavelet site, and a wikipedia link, both giving information about what that is) to analyze whale songs and then colour coding them (among other things) to aid in visualizing the results. The results are quite striking, I hope you agree, and here’s another:
There’s a New York Times article on his work that can be found here, and from which I quote:
Mr. Fischer creates visual art from sound using wavelets. Once relatively obscure, wavelets are being used in applications as diverse as JPEG image compression, high definition television and earthquake research, said Gilbert Strang, a math professor at the Massachusetts Institute of Technology and an expert on wavelets.
They are popular now in part because they can capture intricate detail without losing the bigger picture, and when presented in circular form (using a cylindrical coordinate system [click on image at right -cvj]), repeated patterns are even more evident. By stringing successive images together, Mr. Fischer transforms still images into animated audio files that bring the sound to life.
Fischer is very keen to stress both the scientific and artist value of these representations. His web site is at this link. Scientists working in these areas using more “traditional” methods may well adopt this or similar methods as a tool. Here’s a quote from the article from one of them. For example:
Peter Tyack agrees that the technique has potential not only as art, but as a scientific research tool. A senior scientist at Woods Hole Oceanographic Institution, Dr. Tyack studies the way humpback whales communicate, trying to show that the repetitions in whale songs follow grammatical rules similar to those of human language.
â€œLooking at those figures, it looked like you could see a lot of repeated units,â€ Dr. Tyack said of the images. â€œIt looks like heâ€™s visualizing some of the points that we made in the paper about humpback song.â€
Earlier today Amara Graps, a regular and informative commenter here and on CV told me more about this, and gave me some nice links that she said I can share with you. First, as I pointed out earlier, there’s her website on wavelets in general.
He transforms whale calls using wavelet transforms, and more
recently turned those gorgeous pictures into animations playing
simultaneously with the calls. Here are his animations on Google Video: (link).
My favorite is this (part of the the Nollman session described
below minus the guitar)
If you go to Amara’s Wavelet Sound Fun page (and who would not want to with a title like that), you’ll learn a bit more about other applications of wavelet transforms, and you can scroll down to the bit on whale song to see more description of Mark’s work.