A walk through the meadow on a warm May day for scientists from the Berlin Museum of Natural History is a real polyphonic concert. At the same time, the tasks for bioacoustic speakers are very serious: they hang voice recorders on trees and set up tripods in the middle of the meadow to fix the twitter of birds using microphones. For several weeks, experts record each sound made by birds. In addition, for research purposes, insects are heard: the buzz of earthen bumblebees over flowers or the twitter of field crickets. Almost everything that makes sounds can be studied from the point of view of bioacoustics, sometimes researchers listen to entire ecosystems, since the sound of nature is an important indicator of its condition.
My project takes place in an art gallery. And one of the exhibitions, which I designed, is connected with sound. It is very popular with ESK volunteers. I give her tours. The topic of sound is interesting not only to me, but to the rest of the volunteer. I think sound is a very unexplored topic. Volunteers on excursions often ask me about experimental music. In particular, is it possible to make music from the meow of koto or from the noise of trees. I did not know what to answer. It was difficult for me, but later, I thought why, I can’t close the gap in my knowledge and study this issue. I myself will learn new things, and then I will teach everyone two years later. After all, erudition will never hurt a volunteer. Moreover, if I decided to connect my life with art, then it will be very useful for me.
During my project, I became interested in the topic of experiments with sound. To my young colleagues, this also seemed interesting enough, and I decided to make it out. It all started with the fact that at the time of the project, the apartment where I live is next to the рощ And often I wake up from the fact that the birds chirp very loudly. Sometimes it’s annoying, but often it’s very beautiful. And I thought, is it possible to create music from these sounds?
“In the virgin meadow, I hope we hear a lot of larks. This, of course, always depends on where the meadow is,” says Karl-Heinz Frommolt, head of the archive of animal voices at the Museum of Natural History. Together with fellow zoologists, he tries to accurately identify by hearing individual species of birds against a general background of buzzing and twittering. To accurately recognize local bird species, a highly trained ear is required, says Frommolt. At the same time, modern technologies help: the so-called pattern recognition algorithms can already well "hear" many types of animals. At least, if the records feature only one species of representative fauna and several background sounds. However, in the wild, sound chaos usually reigns.
The new sensory system, which Frommolt and colleagues are now testing in the Lower Oder Valley National Park, is called to automatically recognize the voices of individual bird species and determine their location against the background of such a sound disorder. The novelty is tested on corostelas, - about fifty pairs of this endangered species of birds breed in the meadows. If the grass mows at the wrong time, it scares away the corncrake from its nests. The new sensory system establishes not only the fact that the bird lives in a particular area, but also the exact location of the bird. To do this, four microphones simultaneously record ambient noise, and the software recognizes the birds and indicates their locations in real time. This is what gives scientists the opportunity to understand which parts of the meadow can be mowed without frightening the coronel.
Berlin zoologists have focused on only one type of bird, while their other colleagues are trying to decipher the sound palette of entire ecosystems. Science has come to the conclusion that each site of a homogeneous geospace - a biotope - has a unique acoustic code, like human fingerprints. At the same time, animals are so tuned to each other that they seek to hear as many species of fauna as possible, each of which sings, squeals or roars in its frequency range.
One of the pioneers of "sound ecology" was the German musician Bernie Krause, for over half a century he has been recording natural symphonies - forest wind, bird chirping, subtle sounds of sea corals or insect larvae. Starting with mixing the voices of nature with electronic sounds, he eventually left the music to devote himself to bioacoustics. Once in the Kenyan savannah, Krause had the idea that the voices of the animal world resemble an orchestral arrangement: insects chirp at high frequencies, and the roar of predators comes from afar in the low range, and in the common choir everyone finds their place. Based on this, Bernie deduced the so-called niche acoustic theory: in an untouched ecosystem, all frequencies are occupied, while no sound overlaps another.
In my project, it helps me to know that the voices of the animal world resemble an orchestral arrangement: insects chirp at high frequencies, and the roar of predators comes from far away in the low range, and in the general choir everyone finds their place. Based on this knowledge of acoustic theory: in an untouched ecosystem, all frequencies are occupied, while no sound overlaps another. It’s easy for me to show during the tour which tools are similar to animals. When you conduct a tour for children, they more easily remember this in direct associations. A cow is a saxophone bass, Capercaillie is an oboe. In this way, Sergey Prokofev, the great Russian classic, walked during the composition "Petya and the Wolf".
Based on acoustic data, I studied how land use, depending on its intensity, affects various environmental processes. I worked with volunteers with the so-called acoustic index, which shows how the recorded sounds are distributed over different frequency ranges.