Listen to this recording. It sounds a little like Sputnik, but it's actually a noise that's not been heard in 165 million years.
This is the song of an extinct species of bush cricket, the fossils of which have been found in China's Inner Mongolia region. Researchers recreated the sound by studying the fossil remains of the crickets' sound-producing organs. From the BBC:
A "plectrum" on one wing was dragged along a microscopic comb-like structure on the other. This produces a continuous "chirp" as the male insects rub, or "stridulate" their wings in a scissor-like motion. Dr Zapata described this stridulation as similar to playing a tiny violin.
Dr Zapata then set out to calculate the frequency of the tone, which denotes how high- or low-pitched it sounded. To to this, he simply compared the size and shape of its music-making or "stridulatory" instruments to those of living cricket species
There are modern bush crickets, but their songs are played at a higher pitch. The low tones produced by this extinct cricket imply that it might have been best adapted to do its singing on the ground, rather than elevated on branches or tall stalks of grass. Lower pitched sounds travel further from that elevation than a high-pitched one would.
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