Why do dolphins and bats use high-pitch noises instead of low-pitch noises for echolocation?

Question

Maya Anderson · Accepted Answer

When dolphins or bats are using echolocation, they use high pitch noises to avoid objects they cannot immediately see, or to home in on prey, or to avoid a predator.

The animals use high pitched sounds to navigate, hunt and survive. A bat can echolocate an insect, one meter away, while flying : within 6 millisecond. The brain and ear of animals using echolocation are specially evolved to process/interprete the sound they emit and the echo they receive. It is true that low frequency sound travels further but aimals using echolocation must avoid obstacles in their way during flight and may have to follow prey which could be done better by using high frequency sound. Position, size, and speed of prey can also be assessed in detail. High pitched sounds are convenient because they can be tailored to be unnoticed by the prey the animals are hunting. Bouncing signals off submerged outcrops or cave walls allows them to swim or fly swiftly through tight surroundings. Their high pitch sounds cannot be tracked by predators, but they allow the animals to keep track of each other so they can stay together and still avoid collisions with each other. Many of these echolocation species have a range of sounds they can use, but the high pitch sounds are used most when hunting or when in flight from prey. A noise or sound that is defined as high-pitched will have the characteristic of being a high frequency sound. Dolphins can recognize frequencies up to #200 KHz#, while bats can receive up to #120 KHz# signals. Human hearing is in the range of #20Hz to 20KHz#. Caution: The high pitch may be incorrectly construed to indicate a higher communication speed for the animals, but the #speed# of the returning wave is dependent on the properties of the medium and is independent of the frequency. You can hear the bat signal here: https://tutor.hix.ai Dolphins: https://tutor.hix.ai Bats: https://tutor.hix.ai

Piper Anderson · Answer

undefined Dolphins and bats use high-pitch noises for echolocation because higher frequencies provide more detailed information about their surroundings due to shorter wavelengths, allowing for better detection of small objects and navigation in complex environments.