Brief Explanation of echolocation
It can be described as the use of echoes and sound waves to detect and determine the position of objects. It is commonly used in animals to detect objects in space. An example is a bat that produces sounds from its mouth to detect objects when the sound waves produce echoes which bounce back (Van Ryckegham, paragraph 2). Echolocation is characterized by the intensity, frequency, and duration of the sound waves. Humans can also use echolocation albeit with some form of training. The concept of echolocation is used in sonar and radar systems and technologies.
Summary of the article by Rice and Feinstein
Rice and Feinstein experiment using four blind subjects to find out if they could differentiate objects placed in front of them. The test subjects were between the ages of 20-30 and completely blind (Rice and Feinstein 1107). The objective of the test was to discover the minimum difference in sizes that could differentiate if an object was larger or smaller. The distance between the subjects and the targets was varied and the results collected for analysis. The experiment concluded that humans are capable of making size discrimination on echolocation which is relatively fine. Rice and Feinstein (1108) state that the degree of acuity in the experiment was equal to the thresholds found in monkeys and sea lions.
The Question posed in the article by Teng and Whitney and the conclusion
The question posed by Teng and Whitney is whether sighted people can be trained to achieve the same levels of acuity exhibited in blind experts. The article proposed the hypothesis that novices who are sighted can discriminate position and size discrimination in echolocation when trained. The experiment in the article used eight sighted subjects to test their acuity in discriminating objects of different sizes at different angles (Teng and Whitney 6). The expert who was used in comparison was an expert who was born blind and taught himself echolocation. The results concluded that with echolocation training, sighted individuals can achieve the same levels of precision to that of a blind expert (Teng and Whitney 7). However, future research should focus on identifying the echolocation cues and time needed for training.
Acuity of echolocation in blind individuals
There is no heightened acuity in blind people when compared to sighted people. It is not a rare ability that is inborn in blind people (Teng and Whitney 6). Blindness can occur at any stage in life due to different reasons. It can be learned by any person. The only difference will be the levels of precision and acuity which will differ. It appears to be heightened in blind people perhaps because they are forced by the lack of sight to compensate for an alternative way to see.
Summary of video by Daniel Kish at TED2015
The video is a presentation by Daniel Kish on his experiences of using echolocation since childhood (TED2015). He suffered blindness while a toddler and taught himself how to echolocate. I believe that with training, both sighted and blind people can echolocate. The simple test by Kish using a board to reflect sound shows that it is practical. Using echolocation may be easy to determine the distance from an object but may be harder to differentiate sizes of an object. To visualize an object using echolocation may require significant training from my perspective.
Works Cited
How I use Sonar to Navigate the World.”YouTube, uploaded by Ted, March 2015, www.ted.com/talks/daniel_kish_how_i_use_sonar_to_navigate_the_world. Accessed 8 February 2018.
Rice, Charles and Stephen H. Feinstein. “Sonar Systems of the Blind: Size Discrimination.” Science, volume 148, no. 3673, 1965, pp.1107-1108.
Teng, Santani and David Whitney. “The acuity of echolocation: Spatial resolutions in the sighted compared to exert performance.”J Vis Impair Blind, volume 105, no. 1, pp.20-32.
Van Rychegham, Alain. “How do bats echolocate and how are they adapted to this activity.”Scientific American, 2018, www.scientificamerican.com/article/how-do-bats-echolocate-an/ Accessed 8 February 2018.
