Interesting discovery about grasshopper ears

The ears of grasshoppers are on their feet, but grasshoppers can sound better than humans, a new study says.

In fact, although insects and mammals have separated for a long time in the past, the way the ears work is the same.

A scientist at Bristol University, Daniel Robert and his colleagues focused on the South American locust Copiphora gorgonensis , an orange-colored insect. This insect can listen to sounds in the 5000 to 50,000Hz range, compared to humans that only hear about 20 to 20,000Hz. These insects can emit sounds at a frequency of about 23,000Hz, in ultrasonic waves, or on the frequency range people hear.

The ears of these grasshoppers are less than a millimeter long. When researchers opened them, they found a set of eardrums, unlike humans, whose grasshoppers had two eardrums in each ear. More surprisingly, they found inside the ear a bag filled with fluid. However, scientists have encountered difficulties because these bags break when they find a way to explore.

The co-author of the study, Montealegre-Zapata told LiveScience: 'The whole system exploded. It is clear that the bags are under a pressure '.

Using a variety of techniques from X-ray sensitive microscopy to CT scans (CT, the same technique used in human medicine), researchers were able to replicate re-structure the whole ear of the locust without opening the bag above. They realized that it looked very much like our own ears.

The human ear has three parts: the eardrum, vibrates when sound waves collide, small bones, small bones transmit and amplify these vibrations so that they are transmitted to the third and cochlea. The hairs on the cochlea vibrate to the brain for processing.

These grasshoppers also have a similar system. Their dual eardrum transmits vibrations to a plate that acts as a lever, reinforcing vibrations that can convey to a fluid-filled bag, a simple version of our small bone system. These bags are like a simple cochlea and have fewer sensory hair cells than that of the cochlea.

Robert said the grasshoppers may need a sensitive listening system to distinguish sounds from other grasshoppers and predators like bats.

Grasshoppers emit sounds that have the same frequency range as the bats emitted by the bats to search for food, so it's easy to make mistakes. If the bat finds it, it will be eaten.

Scientists are now studying the ears of other insects, including a species of grasshoppers that produce sounds with frequencies up to 150kHz (150,000Hz). The sound with this frequency has a too short wavelength, so grasshoppers must have super sensitive ear structures to catch these waves.

Based on these findings, researchers are planning to design sensitive microphones and micro-sound sensors.