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Do duck quacks echo - paragraph for marks...

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Scientific Myths: Duck Quacks don’t Echo… Due: 4 April 2019 It is widely believed that duck quacks do not echo - with the increasing popularity of the internet, this myth became widely spread (García, 2018). However, an experiment conducted by Professor Trevor Cox of the Salford University Acoustics Research Center in 2003 disproved this myth (Amos, 2003). Theories are bound as to the origin of this myth. However, there is some consensus in the scientific community that the myth originated as a result of the fact that a ducks quack echoes in such a way that the echo is masked by the sound of the quack itself (Amos, 2003). Other theories include the idea that ducks don’t quack near echoing surfaces (in other words, their habitats typically consist of large open spaces) and that duck quacks are too quiet to produce an audible echo (University of Salford, n.d.). In 2003, Professor Trevor Cox and his colleagues at Salford University’s Acoustics Research Center placed a duck named Daisy in an anechoic chamber1. Using computer tools, the researchers were able to simulate Daisy’s noises in a variety of environments (Amos, 2003). The study found that duck quacks do echo. However, the sound of the echo merges with that of the quack as the quack fades, resulting in what sounds like a single long quack, rather than a distinguishable quack and echo (Amos, 2003). During these experiments, it was also noted that Daisy’s quack was so quiet that her echo was almost inaudible in certain environments (Emery, 2018). Similar experiments were also conducted by investigators on the television show, MythBusters where it was found that the echo was essentially absorbed by the original quack due to the very similar acoustic structure between the quack and the echo (Emery, 2018). Figure 1 shows how the echo of a duck’s quack is essentially the reverberation of the sound waves off of a surface. Professor Cox’s experiments found that the sound waves of the echo and the sound waves of the quack essentially superimpose (as shown by Figure 2), which results in a substantial reduction in the volume of the echo (PhysLink.com, n.d.).

Figure 1

Figure 2

Professor Trevor Cox stated in his findings, “because the duck’s quack is rather quiet anyway and the echo comes on the back of a fading sound field, it is as if the echo is being masked. You just don’t hear the echo very well and that’s probably how the myth arose” (Amos, 2003). References: Amos, J., 2003. Sound science is quackers. [Online] Available at: http://news.bbc.co.uk/2/hi/science/nature/3086890.stm [Accessed 08 03 2019]. Emery, D., 2018. Myth Busted: Does a Duck's Quack Echo?. [Online] Available at: https://www.thoughtco.com/myth-busted-a-ducks-quack-doesnt-echo-3298983 [Accessed 08 03 2019]. García, D. G., 2018. Myth: Duck’s quack has no echo. [Online] Available at: http://www.geomicrobes.com/myth-ducks-quack-has-no-echoo/ [Accessed 08 03 2019]. National Geographic, 2014. The Truth Hurts | Duck Quacks Don't Echo. [Online] Available at: https://www.youtube.com/watch?v=qTP2cjBrGnM [Accessed 08 03 2019]. 1

a chamber that deadens all echoes

PhysLink.com, n.d. Is it true that a duck's quack doesn't echo? If so, why?. [Online] Available at: https://www.physlink.com/education/askexperts/ae482.cfm [Accessed 03 04 2019]. University of Salford, n.d. "A Duck's Quack Doesn't Echo, and no-one knows the reason why?". [Online] Available at: http://www.acoustics.salford.ac.uk/acoustics_info/duck/ [Accessed 08 03 2019].

By Erin van den Heever (22547134) and Sarah Scott (22564888)...