Cicadas are insects known for their distinctive and loud sounds. Their periodic emergences, when large numbers appear simultaneously, are a natural phenomenon. This presence sparks curiosity, especially regarding the intensity of the noise they produce.
The Decibel Level of Cicadas
Cicadas are some of the loudest insects globally. Their sound intensity varies significantly by species.
The African cicada, Brevisana brevis, holds a record for its calling song, reaching approximately 106.7 decibels when measured from 50 centimeters away. North American species, such as Tibicen walkeri and T. resh, have produced alarm calls around 105.9 decibels at the same distance.
Individual cicadas generally generate sounds between 80 and 120 decibels at close proximity. When multiple cicadas chorus, the sustained noise can reach about 88.5 decibels. Periodical cicadas, like those in Brood X, produce sounds up to 100 decibels.
How Cicadas Produce Sound
Male cicadas produce loud sounds using specialized structures called tymbals. These are ribbed membranes located on the sides of their abdomen, not vocal cords. A powerful muscle rapidly contracts, causing the tymbal to buckle inward and produce a distinct click.
When the muscle relaxes, the tymbal springs back, creating another click. This rapid inward and outward movement, often hundreds of times per second, generates the continuous buzzing or whirring sound. The cicada’s body also contains large, hollow air sacs that act as resonance chambers, amplifying the sound produced by the tymbals.
Comparing Their Sound to Everyday Noises
To understand the intensity of cicada sounds, it helps to compare them with common daily noises. A normal conversation registers around 60 to 70 decibels. A vacuum cleaner operates between 60 and 80 decibels, while busy street traffic can reach 70 to 85 decibels.
Cicada choruses, often around 88.5 decibels, are comparable to a gas-powered lawnmower (85-100 decibels). Individual cicadas or specific species, reaching over 100 decibels, can be as loud as a passing motorcycle (91-116 decibels). Some cicada calls even approach the intensity of a car horn, peaking between 100 and 110 decibels.
Hearing Safety and Cicadas
Understanding cicada decibel levels leads to questions about hearing safety. Sounds at or below 70 decibels are generally safe for prolonged exposure. However, sustained or repeated exposure to noise at or above 85 decibels can lead to hearing damage over time. The louder a sound, the less time it takes for potential harm.
Since cicada choruses can reach 100 decibels or more at close range, exposure for as little as 15 minutes can contribute to noise-induced hearing loss. This damage typically results from repeated exposure, not a single instance. Prolonged exposure to loud noise can also cause tinnitus, a ringing or buzzing sensation. To minimize risks, maintain distance from extremely loud cicada activity. If close proximity is unavoidable, use hearing protection like earplugs or headphones.