What describes the sound of cicadas chirping in summer?

It can be described as "cicada", which is an onomatopoeia.

Or use "chichi", "chichi" and other sounds. The cicada's cries are very loud, high and low, one after another, like playing a beautiful piece of music. The cicada's voice is full of infinite tension, as if there is a player installed in the body. As long as life lasts, it will sing every day.

Life habits:

The male cicada can sing. Its vocal organ is located in the abdominal muscles, like a big drum covered with a layer of tympanic membrane. The tympanic membrane is vibrated to produce sound. The muscle can stretch and contract about 10,000 times per second, and there is an empty space between the cover and the tympanic membrane, which can play the role of ringing, so the ringing sound is particularly loud. And can take turns to use a variety of different tones to sing passionately. Male cicadas sing non-stop every day to lure female cicadas to mate. They cannot hear their "singing".

Male cicadas of each species emit three different calls: a gathering call, which is regulated by daily weather changes and other male cicada calls; a courtship call before mating; and a call when caught or frightened. A loud squeak when walking away. The female cicada's instrument structure is incomplete and cannot produce sound, so it is a "dumb cicada". Some species are easier to identify based on their song, behavior, and morphology.