The echo consists of the repetition of a sound, produced by an acoustic phenomenon.
The echo is the repetition of a sound by an acoustic phenomenon that consists of the reflection of the sound wave in a hard body. Once reflected, the sound returns to the place of origin with a certain delay and, in this way, the ear distinguishes it as another independent sound.
The minimum delay necessary for this phenomenon to occur varies depending on the type of sound. In cases in which the sound is deformed so much that it becomes unrecognizable, it is called reverberation .
For example: “The echo of his voice in the cathedral made it difficult to understand the songs,” “On vacation I went to the mountains with my parents and we played with the echo that was generated by shouting on the cliffs,” “I need you to come down .” the volume of the television as the phone echoes” .
Symbolic uses of the concept
This acoustic phenomenon also allows us to use the concept of echo (which comes from the Latin echo ) in a symbolic way. In this way, the person who repeats what another says is also known as an echo, as are sayings that are markedly influenced by a precedent: “He wants to present himself as a new candidate, but he is nothing more than the echo of the old political leader.” of the people” , “I ask you to point out my errors, not to be my echo and join everything I say” .
The sound that is faintly perceived, the vague rumor of an event and the repercussion of a news story are other ideas that can be expressed through the notion of echo: “The echo of the player's statements reached the club and sparked controversy” , “The echo of the bombs can be heard throughout the region.”
Echolocation is a resource of certain animals that can detect the objects around them by analyzing the echo of the sounds they emit.
Echolocation
Also known as echolocation , echolocation is a mechanism used by some animal species for the purpose of detecting objects around them. Basically, it consists of the emission of sounds and the subsequent analysis of their echoes. It is worth mentioning that unlike sonar, developed to assist navigators, animals have several receptors.
Among the mammals that use echolocation are bats (with some exceptions), sperm whales and dolphins. With respect to oviparous birds, we can mention the guacharos (also known as cave birds ), swiftlets and swifts. Some scientists have tried to prove that humans also possess this ability to some extent, but no one has yet presented irrefutable evidence.
By interpreting the echo, the animals are able to measure the distance they are from the detected objects, taking the sound delay time as fundamental data. Furthermore, the fact that each ear perceives the echo at different times, with a different intensity and frequency, allows the recreation of the size and certain characteristics of the elements, more complex than their mere position.
The case of the bats
Despite what many think, bats have the sense of sight, and some use it to orient themselves and hunt during the day, reserving echolocation for flights in absolute darkness . In these cases, in addition to detecting their prey, they use this resource to avoid dangers such as areas inhabited by predators and to find a source of insects that have not been found by many hunters.
Ultrasound is generated in the larynx and emitted through the mouth or nose, to form a call whose frequency range goes from 14,000 to 100,000 Hz, 80,000 Hz above the limits of our auditory perception. On the other hand, these same animals are capable of producing sounds of considerably low frequencies, reaching 10 Hz.