I would like to say that for all of the screaming that we hear about "evil corporations," we should consider that the actions of some do not represent a whole. Sparton Navigation and Exploration, who manufactured the two hydrophones that I borrowed from Embry-Riddle, is based in DeLeon Springs, Florida. We called them, hoping to see if they might have some nature of program for educational institutions. They not only offered an exceptional deal on future procurement, but they donated the first hydrophone!
There is still a bit of technical housekeeping to be done before we dive, but we are finally "over the hill" on the major technical hurdles that had to be crossed in order to bring this project to fruition.
That is all for project updates, so let's answer some recent questions.
Aleecia, from DSC's OCE1001 class, writes:
"...what are the different shapes you are going to look at and why these shapes?"
I'm glad you asked. First, let's think about what we know about sound. It's a wavelength, transmitted from one source, and received by one or more sources in one or more locations. The basic components of a sound wave are frequency, wavelength, and amplitude. The wavelength is the period of one cycle, the amplitude is the strength or pressure of the wave, and the frequency is how many times the wave cycles in one second. We measure those cycles in units called Hertz (Hz), which obviously give way to kilohertz (kHz) and megahertz (MHz). Everything we know about capturing specific wavelengths, usually revolves around shallow conical shapes like dishes. For the sake of this experiment, we will have 0° flat plates to act as a control, followed by 15° and 25° dishes, and finally a 90° "can" shape. If the dishes work as we believe they should, then we will be able to see the difference between them in the readout data, and that will give us a direction to go. The 90° "can" shape is inspired by collector shapes of certain unidirectional radio antennas already in use, so since we will already be diving, we will try this shape as well to get data from our "extreme" limit. No one has yet mastered unidirectional sound collection underwater, but hopefully the variance we've built into this experiment will give us some direction.
"Do you plan on using it to study dolphins in the wild or in captivity?... Do you think your prototype will be able to move as needed to study the dolphins? And while it's moving, will you have sound interference from the water's movement?"
I am lumping all three questions together, for one finite answer. I am developing this system so that everyone who studies underwater organisms will be able to collect a wealth of specific sounds, without much movement themselves. There have not yet been discussions of ROV-mounted variants, though I would love to see that be a future possibility. I am starting simple, with considerations towards a diver-carried unit. Dolphins, like us, breathe atmosphere in order to conduct cellular respiration. This means the majority of their communication occurs in congregated social groups in limited spaces. Why not communicate while swimming across the ocean at high speeds? Well, they have the same problem that the runners of our species do: they're too busy breathing.
Our intention with this device is to allow a diver from the outside of a biological family group to listen in on specific sounds from within the group, without getting close. This way, the diver doesn't risk disturbing an otherwise natural interaction. So, a bit of water movement can be filtered out with software, but there is little risk of high-speed movement becoming an issue.
As the technology continues to develop, it will be important to study both captive and wild family groups, so as to better compare data. Through this, we can group what sounds can constitute common "language" for the species, versus sounds that are attributed to one group or the other.
Thanks for the questions Aleecia, and I look forward to more from everyone else!
Aleecia sec. 65: I think i understand that your goal is to record and monitor dolphin sounds as they relate to their auditory and behavioral communication structure. So my question: dolphins (i think) travel in groups. When dolphins make their sounds (clicks, whistles) can you see the specific dolphin making these sounds? In other words, I can make sounds without opening my mouth. If i was in a crowded room and made this sound, how are you going to be able to tell it's me and then relate that to any obvious behavior? So what does a dolphin look like when they make these sounds? Is it obvious enough to know which specific dolphin made it? i hope this makes sense.
ReplyDeleteWilliam, Sec. 51. This is a really cool project! Based on the information in our post (e.g., 90 degrees) I can't say I really understand your dish shapes. BUT, I have read articles where architects and some engineers are now creating buildings and various structures based on shapes found in nature. Have you considered looking at the shape of the dolphin's 'dish' and using that as your shape?
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