Before the development of radar, approaching airplanes were often detected and localized acoustically. To increase the range and precision of airplane localization, people built a range of devices to enhance human hearing. Below are some pictures of such devices. The following article provides some further explanation.
How warplanes were spotted before radar | CNN
All these devices attempted to increase the cues available for sound localization. In the current activity, students are asked to build their own devices to enhance sound localization. The activity is described on the following page.
Tell students they will pair up for their sound localization test. They will also be tasked with building pinnae to enhance their ability to locate sound, and then testing the effectiveness of their design. For inspiration, show students some pictures of acoustic locators built in the early 20th century. You can also show them pictures of various animal ears. We previously provided students with cardboard paper, pipe cleaners, tape, etc., to build artificial pinnae. Example of some ears built by our students can be seen in the images below.
Picture of students engaged in the experiment, testing their self-made external pinnae. The large sheet of paper on the floor is not part of the current activity.
The Google Doc embedded below can be printed and handed out to students as a handout describing how to conduct the experiment and record the data.
After all groups have finished, discuss the pinnae's performance. In their designs, students could have affected the timing (through distance), the loudness (through shape), or both. Ask the class questions to gather information about which were most effective and what they might change with more time.
For this activity, students should download a sound snippet. The link is provided in the linked Google Doc below. However, they can also download it directly here (click the file, then click the 3 dots to download).
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You can decrease the number of trials if time is short.
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https://docs.google.com/document/d/1V8dXweQiOUJKbkWrg74FiriQjNVoPsODYCXSUl_M6s8/edit?usp=drive_web