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Every location has a soundscape. Not only does it exist on land but in the ocean. The creatures that live in these environments are part of the soundscape, including the ones that echolocate. When animals such as bats and dolphins emit the sounds that detect the landscape around them they are contributing to the soundscape. These sounds that are used for echolocation are part of the natural soundscape unlike those of emitted by sonar and radar used by the military. When sonar and radar release the sound pulse it creates noise pollution, disturbing and disrupting the natural soundscape. It can prove hazardous for animals that use echolocation. Sonar sounds in some cases cause temporary deafness in dolphins and has been linked to cases of marine life that use echolocation stranding themselves.
The sound clip is that of the undisturbed natural soundscape of a bat. In the background it is possible to hear normal nighttime sounds including that of a cricket. The main sound is that of the bat while using echolocation to navigate and hunt. Each screech that the bat produces enables it to determine the terrain including the difference between land and water along with the location of any passing insects. Military radar and sonar use the same system except that instead of insects they are searching for passing enemy planes, ships and submarines.
The way that humans have advanced their use of technology past the point of the basic stone and stick is one of the things that separates them from the rest of the species on the planet. Inspiration for new types of technology comes from the world around us. Often people look to their natural environment in search for ideas to improve their lives. Ideas such as solar energy come from the knowledge that plants convert sunlight into energy that is used to sustain them. In an attempt to further improve the process scientists have taken to studying the process of photosynthesis in an effort to make it more effective. Echolocation has followed the same process. The military saw that dolphins and bats use echolocation to locate objects in their surroundings. They then adapted it in to sonar and radar. In an effort to make them more effective they studied in detail the animals that developed echolocation for their survival.
Echolocation differs between aquatic and land animals due to the difference in their environments. The way that echolocation works even differs between the individual species of bats and dolphins. For some species echolocation is their sole method of orientation while others posses limited eyesight. In some of the cases that animals possess eyesight and echolocation they use them interchangeably. The different species emit sounds at different frequencies. In all cases of true echolocation there is both the ability to emit and receive an ultrasonic sound. Part of the reception of the sound happens in the brain. “There are different relationships between the cortical and subcortical divisions of the brain in bats as compared with other mammals” (Airapet’yants 277). Other portions of the brain are also affected echolocation. The area of the brain that is in charge of echolocation is separate but essential.
With new advances in warfare there came to be a need new advances in counter warfare. The development of sonar and radar are part of this process. “Electronics in war… [began] to affect the whole character of war” (Devereux XV). Radar and sonar were used in both of the major wars of the twentieth century. They were invented using the already developed radio. The radio was developed as communication in the late nineteenth century. A German inventor patented the radar in 1904 when he noticed that radio waves would bounce off of a passing ship. The first sonar was patented in 1912 and more research was done when there became the need to detect German U-boats or submarines during World War I.
Further studies were done with the goal of making military echolocation more effective. To do so examples were needed of successful examples. This is when the military turned to animals that had developed the adaptation. The natural equivalent to radar is bats and the natural equivalent to sonar are dolphins. “The Navy’s sonar program and civilian marine mammal research program were linked during World War II” (Axtell 206). There are two types of sonar: active and passive. Marine mammals use active sonar while the sonar in military aquatic vessels was passive. Active sonar is when a sound is sent out, bounces off objects and returns while passive sonar is when the sounds made by other objects are listened for. The military now uses a combination of passive and active sonar.
A major way of learning is through the use of examples. Initially the military was able to develop their own methods of echolocation to determine the objects in their surroundings. In efforts to improve the military worked with who made a study of the animals that adapted to use echolocation. In some cases dolphins were used directly my the military “to sweep for mines, recover lost ordnance, and detect enemy ‘frogmen’ at sea” (Axtell 206). Currently the echolocation systems of the military have become every effective tools. They are different from those of bats and dolphins however. Animal echolocation provides a detailed account of the area in a close range while machines provide a general account of information on the area but at long distances. “‘Live locators’ are a cause for envy among engineers” for their ability to accumulate detail (Airapet’yants 279).