This lesson plan can be connected to a career-ready path, as it focuses on important concepts related to biodiversity and the impact of human activities on it. Students who are interested in pursuing careers in biology, environmental science, ecology, conservation, or other related fields would benefit from gaining knowledge and skills related to biodiversity. Additionally, the research skills, critical thinking, and problem-solving skills that students will develop in this lesson can be applied to a variety of careers. For example, individuals who work in conservation or environmental science may need to evaluate the impact of human activities on biodiversity and design solutions to mitigate negative effects. Overall, this lesson plan can help students gain valuable knowledge and skills that are relevant to a wide range of careers in the STEM fields.

Students work as if they are electrical engineers to program a keyboard to play different audible tones depending on where a sensor is pressed. They construct the keyboard from a soft potentiometer, an Arduino capable board, and a small speaker. The soft potentiometer “keyboard” responds to the pressure of touch on its eight “keys” (C, D, E, F, G, A, B, C) and feeds an input signal to the Arduino-capable board. Each group programs a board to take the input and send an output signal to the speaker to produce a tone that is dependent on the input signal—that is, which “key” is pressed. After the keyboard is working, students play "Twinkle, Twinkle, Little Star" and (if time allows) modify the code so that different keys or a different number of notes can be played.

Students learn about sound and sound energy as they gather evidence that sound travels in waves. Teams work through five activity stations that provide different perspectives on how sound can be seen and felt. At one station, students observe oobleck (a shear-thickening fluid made of cornstarch and water) “dance” on a speaker as it interacts with sound waves (see Figure 1). At another station, the water or grain inside a petri dish placed on a speaker moves and make patterns, giving students a visual understanding of the wave properties of sound. At another station, students use objects of various materials and shapes (such as Styrofoam, paper, cardboard, foil) to amplify or distort the sound output of a homemade speaker (made from another TeachEngineering activity). At another station, students complete practice problems, drawing waves of varying amplitude and frequency. And at another station, they experiment with string (and guitar wire and stringed instruments, if available) to investigate how string tightness influences the plucked sound generated, and relate this sound to high/low frequency. A worksheet guides them through the five stations. Some or all of the stations may be included, depending on class size, resources and available instructors/aides, and this activity is ideal for an engineering family event.

Students are introduced to the role of electricity and magnetism as they build speakers. They also explore the properties of magnets, create electromagnets, and determine the directions of magnetic fields. They conduct a scientific experiment and show cause-effect relationships by monitoring changes in the speaker's movement as the amount or the direction of the current change.