(By James Gorman)

I sympathize with the Brazilian white-banded tree frog, at least the ones subjected to recorded bullfrog calls, because I myself have had some negative experiences with recorded cricket noises.

I’ll get to my story later. First, what happened to the tree frog is that there it was, minding its own business in a Brazilian pond, calling out for a mate, as tree frogs do.

“Here I am,” it called, “oh, female white-banded tree frogs, here I am.” And then, out of the blue, or probably the green, came the aggressive bray of a North American bullfrog.

“Yo, Adrian! Yo, Adrian!” the bullfrog croaked. (Or something to that effect. All amphibian calls in this article are loosely translated.)

The croak overwhelmed the calls of the tree frogs, as well as those of other pond dwellers, and the tree frog raised its voice to a higher frequency to rise above the bullfrog clamor.

We know this happened because scientists went to ponds in a Brazilian national park that had been invaded by bullfrogs, and played a bullfrog’s recorded croak, directing it at specific tree frogs. They also recorded the tree frogs before, during and after the croaking of the virtual bullfrog.

They were exploring the idea that in addition to taking up space and eating whatever it could fit in its mouth, the bullfrog was an acoustic invader, forcing the the tree frog to find a new “acoustic niche.”

That’s the term used by the scientists who conducted the experiment, Camila Both of the Pontifical Catholic University of Rio Grande do Sul and Taran Grant of the University of São Paulo, in Brazil. They reported the results of the simulated audio invasion online on Wednesday in Biology Letters. (More frog sounds can be found here.)

The bullfrog is a problematic invasive species that spread from its original habitat in the Northeastern United States to much of the rest of the country and to Europe, Africa and South America. And the acoustic invasion of the soundscape, the scientists say, is as real as the physical one, and should be considered in assessing the effects of other invasive species as well.

The idea of soundscapes, and of audio ecology, was put forth by R. Murray Schafer, a Canadian composer and thinker who published “The Tuning of the World” in 1977. Since then, these ideas have become part of cultural and environmental thinking.

Often the soundscapes are divided into natural and human. But what struck me about the bullfrog experiment was how mixed up the soundscapes have become. Scientists, hunters and birders routinely play recordings of wild creatures to other wild creatures. If a natural sound is perfectly reproduced in its appropriate environment, is it natural or unnatural?

Once, you had to have some sophisticated equipment to acquire natural sounds and take them back into nature in unnatural form. Now all you need is a cellphone. I used to have a loon as a ringtone. Researchers themselves are making their recordings available as ringtones. Rodney Rountree, a marine biologist at the University of Massachusetts in Amherst, offers ringtones on the Web to raise money for research.

By far the most popular involve fish flatulence, he said, “but the cusk eel, toadfish and sea robin sounds make much better ringtones.”

It is all confusing —at least for me, and I bet for more than a few wild creatures. Which brings me to the cricket. One night a while ago, I heard a cricket sound and started crawling around my bedroom, half asleep on hands and knees, trying to find the source.

The thing is, I didn’t know whether I was looking for an insect or a cellphone, because I had at one time used a cricket sound as an alarm on my phone.

I am going to get a new ringtone for a phone I just bought, but it will not be something that could occur naturally in my office or house.

Right now I’m thinking of a cusk eel. (Courtensy: NYT)