Here I come with a first entry about the newly created category The soundscape (Schafer);
»The most easily recognized insect sounds for modern man are the most irritating. The mosquito, the fly and the wasp are easily distinguishable. The attentive listener can even tell the difference between male and female mosquitoes, the male usually sounding at a higher pitch. But only a specialist, such as a beekeeper, knows how to distinguish all the variants of the bee sound. Leo Tolstoy kept bees on his estate, and their sound is described in both Anna Karenina and War and Peace. “His ears were filled with the incessant hum in various notes, now the busy hum of the working bee flying quickly off, then the blaring of the lazy drone, and the excited buzz of the bees on guard protecting their property from the enemy and preparing to sting.” When a queenless hive is dying, the beekeeper knows this too from the sound.
»The sounds of insects are produced in a surprising number of ways. Some, such as those of the mosquito and the drone bee, result from wing vibrations alone. The general range of wing frequencies in insects is between 4 and upward of 1,100 beats per second, and much of the pitched sound we hear from insects is produced by these oscillations. But when the butterfly moves its wings at between 5 and 10 times per second, the result is too faint and too low to be registered. In the honeybee, the wing beat frequency is 200 to 250 cycles per second and thc mosquito has been measured at up to 587 cycles per second. These frequencies would thus be the fundamentals of the resulting sounds, but as a rich spectrum of harmonics is also often present, the result may be a blurred noise with little discernible sensation of pitch.
»Among the loudest of insects are the cicadas. They produce sound by means of ridged membranes or tymbals of parchment-like texture, close to the junction of the thorax and abdomen, which are set in motion by a powerful muscle attached to the inner surface; this mechanism produces a series of clicks in the same manner as does a tin lid when pressed in by the finger. The movement of the tymbals (amounting to a frequency of about 4,500 c.p.s.) is greatly amplified by the air chamber that makes up the bulk of the abdomen, so that the sound has been heard as far as half a mile away.
»Difficulties have been encountered in the analysis of the precise intensities and frequencies of insect sounds. This is because individual specimens are hard to isolate for recording purposes and also because the sounds insects make are generally complex frequency structures or broadband noises, with harmonics often rising into the ultrasonic range. The locust Schisfocera gregaria emits a sound of about 25 decibels when recorded very near the source, but the wing beat noise rises to 50 decibels when in flight. The flight noise of the desert locust has been measured as high as 67 decibels at a distance of 10 centimeters from the microphone. The sound output of many moths may be as little as 20 decibels quite near the source while insects with hard wings and bodies, such as flies, bees and beetles, produce sounds up to 50 or 60 decibels. Since the human ear is more sensitive to sounds in the middle and upper frequency areas, insect sounds in the upper range (an average might be 400 to 1,000 c.p.s.) sound louder to the ear but no human ear can hear the higher frequencies of the locust’ s call, which have been found to contain frequencies of 90,000 c.p.s., thats is about two octaves higher than human ear can detect.
»Many insect sounds are pulse modulated or varied in other subtle ways, but despite the “grainy” effect such modulations create, the impression with many insects is of a continuous, unvarying monotony. Like the straight line in space, the flat line in sound rarely occurs in nature, and we will not encounter it again until the Industrial Revolution introduces the modern engine.
Having read that, specially about cicada, I’ll forward you to a recording I made in Cambodia, north of Khmer temples, Kulen Mountain, where a really psichedelic sound scared me in the middle of the jungle. I asked a local guy about it, after recording.
He said something like ‘sikada’, and that I wrote on my notebook.