I have done some more research about frogs and how they hear. I was correct in my assumption that they do hear differently from humans and probably many mammals, however I cannot determine if this would affect the way they would here digitally reproduced sounds. I found out a few very interesting key facts about frog ears, though, that I had no idea about before.
First of all, frogs do have ears! While having big floppy ears like we do would affect their aquatic dynamics, they instead have flat disc-like structures located on each side of their heads called tympanum (drum). These structures can vary in size depending on the type of frog and the frequency of its call. However, this is not the only structure that frogs use to hear with; they also use their lungs as a kind of drum that vibrates as well in order to absorb sounds. Researchers believe that they have adapted these structures because of the high decibel of their calls. Frogs use their call to attract mates from extremely long distances or to ward off other potential rivals, thus the louder the call, the more successful and reproductive the frog. If humans were proportionally as loud as frogs we would blow out our ears, but the duel drum and lung hearing system that frogs use allow them to keep their ears safe from themselves. Each ear also hears independently of the other, rather than synthesizing noises that enter both ears, like ours do, the frog processes sounds on a directional basis. This was probably developed in order to protect the ears from loud noises, but also to defend the frog against predators because they can more easily pinpoint the location of threatening sounds.
This could explain why the noises I have been playing back to them do not have the same effect that they do on a human or a dog, perhaps the lung vibration system does not process the frequency of digitally reproduced sounds the way that they have been designed to be heard. Perhaps digitizing the noise changes the frequency or wavelength of the sound in a way that either cannot be hear or confuses the frog.
I have been trying to think of project I could do with this knowledge in collaboration with some on the frogs that I was working with on campus, or at least inspired by them. I am most intrigued by the idea of creating some sort of wearable device that would force humans to hear more like a frog. In my mind I am imagining something like head phones outfitted with funnels going out from each ear, in which I would stick a balloon to act the second level of the vibration absorption system. The funnels would force the user to hear directionally and the balloon would act as very much like the lungs, dampening the high frequency of noises. I would hope the project would at least allow the user to gain a greater insight into how frogs and hopefully different kind of animals in general function in contrast of our own bodies. I would hope to diminish some specieist ideas that the human body function is the best and most important way to perceive the world, and perhaps we would learn from our flat-eared friends about a different way of hearing.
[Write Comment]