Cc:dan@lis.stanford.edu

Subject: Auditory Recognition of Shaped Detonations

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Greetings Dr. Dolata,

I hope to draw on your considerable expertise in a matter pertinent to my master's thesis research (I find it more and more difficult not to capitalize that phrase and I still have months to go...). My thesis is an exploration of the potential to perform shape recognition of virtual auditory objects. Although much of the literature in auditory perception treats sounds as having point sources, it seems that from a physical standpoint this is only seldom the case. Sound sources often have extent and shape to them, although in most natural environments and situations these shapes are not well defined. Take, for example, the sound of an ocean wave breaking on the beach. Although this sound clearly comes from an extended source, it is not clear what its shape would be especially as it changes over time. In fact, in this case, it is the very changing of the shape that creates the sound. In order to establish some physical grounding for a virtual effect, I would like to attempt to synthesize a more "pure" auditory shape.

A few days ago, as I was discussing these ideas with a colleague, he mentioned an anecdote that a he had heard. A mutual friend of ours once claimed that he could hear the shape of lightning strikes from the associated thunder. This friend of ours it somewhat known for his unusual perceptions, but nonetheless I was intrigued by the notion. I wondered if it would be possible to put this claim to the test. The difficulty is-- once again-- that it is impossible to control the shape associated with a random natural phenomenon like lightning. Perhaps another class of violent phenomena would work equally well. One that we more easily synthesize, and in a more controlled fashion: Explosions.

Explosions would be especially good for auditory localization tasks in that their impulse nature makes their frequency spectrum extremely rich. It also occurs to me that it would be quite feasible to control the shape of the event. The system that I immediately thought of (which is clearly the most obvious alternative) is the detonation (implosion?) of hydrogen filled balloon animals.

Several questions initially come to mind to which I do not have the answer:

1) What is the best method of initiating the detonation?

2) What will be the propagation speed of such a detonation across a long balloon?

3) Is it possible to cause simultaneous detonation of multiple balloon cells, or will I be best served by detonating shapes formed of single cells (no twists)?

4) How loud is the detonation likely to be? I need to find the right balance between the perceived angular size of the sound object, and pain/injury thresholds.

There are many other issues which I am fuzzy about, but as I am not versed in pyrotechnics, I am not sure where to go from here.

Perhaps this is the appropriate point in this letter to make it clear that I do not actually expect people to be able recognize the difference between a poodle and a rabbit (if they are REALLY good, MAYBE they could tell the difference between a dachshund and a giraffe). Such abilities are unlikely, due to perceptual factors such as the "Precedence Effect". I do, however, feel it is important that I at least try. Besides, how complete could my thesis possibly be if I did not BLOW THINGS UP IN THE PROCESS!! I envision detonating Hydrogen-filled effigies of the neighbor's poodle as a dozen blindfolded subjects stand nearby drinking good beer, and recording their perceptions. I can hardly imagine a better way to spend a Fourth of July.

Any input, pointers to references, or general advise on this project would be greatly appreciated.

Sincerely,

Ari J. Hollander

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Ari J. Hollander -- ari@hitl.washington.edu

Human Interface Technology Lab, Celestial Mechanic

Lab: (206) 685-8625 #45 Home: (206) 860-8807

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Acknowledgments

I would like to express my gratitude to the following people, without whom this thesis would have been impossible, improbable, and/or impoverished.

My Committee: Dr. Thomas Furness, Dr. Woodrow Barfield, Dr. Robert Duisberg

For sage advice: Dan Shapiro, Maxwell Wells, Werner Steutzle, Suzanne Weghorst, and Joey King

For DLL splammerization and squanque-biscuit baking: Brian Karr

For benevolent cynicism: Joel Kollin, Dan Pirone, Michael Almquist

For inspiration: Dawn Jewell

Dedication to

Dana & Bruce MacDermott, Fred Hollander, & Dan Shapiro
For making this thesis evolutionarily possible in both the Lamarkian and Darwinian senses.

and to

Krzwycy,
Grand High Overlord of All Things That Can Not Eat Him/Her