Articles

Nature’s Loudspeakers

by Jonathan C. O'Quinn

T he noisy calls of cicadas are a familiar evening sound in the springtime. To scientists, the sound production equipment of cicadas is an engineering marvel. The best-known example is a species of Australian cicada, the loudest known insect in the world.

Male cicadas sing their hearts out each evening, hoping to attract females. The male cicada has an elastic, resonant structure called a tymbal, on each side of its abdomen, that produces a series of sharp clicks at a frequency of 4.3 kilohertz, forming the cicada’s song. Each click produces high sound pressures of up to 158 decibels within the cicada’s abdomen.

The abdomen contains a large resonating air sac complete with a pair of large, thin eardrums that act to radiate sound from the body. The eardrums are covered by adjustable plates. By adjusting the length of the abdomen and the position of the eardrum covers, the cicadas can fine-tune

Their abdominal resonation to exactly the 4.3 kilohertz frequency produced by the tymbals.

This produces a high quality song that is more likely to attract females.

This is a major problem for evolution. The intricate design and function of these structures could not have evolved in stages over millions of years, as evolution teaches. Incomplete evolution of any component would render the male cicadas unable to sing, thus making it impossible to attract mates, and leading to immediate extinction.

To those questioning their own origin, the cicada testifies loudly to a planned creation as recorded in the Bible.

Bibliography

Bennet-Clark, H.C. 1998. How cicadas make their noise. Scientific American 278:58-61.

http://www.creationresearch.org/creation_matters/pdf/2004/CM09%2002a.PDF