A VISUAL AND INTERACTIVE LEARNING TOOL: FREQUENCY CONTENT OF SOUND WAVES

Interactive tools and audio-visual aids can be powerful tools in teaching to encourage and enhance learning, and to make the learning process easier, effective and interesting. They help delivering complex concepts to students and provide students' active participation in the process. They convert the process into a more dynamic and active one. Fourier transform is an essential mathematical tool that is used in many engineering courses in different disciplines. The transform explains the fact that every signal or waveform, whether electrical or mechanical, is composed of many sinusoids of different frequencies each having a different weight. This abstract notion of the Fourier transform goes unnoticed or misunderstood by many engineering students. In this work, we design a simple GUI tool using MATLAB, which records a sound sample and shows its frequency spectrum. The spectrum of the human voice shows how different its frequency content might be for different individuals. In addition, we use a function generator mobile app to generate different signals and sounds to show their frequency content and enforce the concept of Fourier transform to engineering majoring students as early as their first year in introductory physics classes. This tool is interactive, intuitive and easy to use and can help students develop a conceptually sound basis of the Fourier transform. Students can try different sounds including their own voice and see immediately the mixture of frequencies they contain. The tool produces a plot of the sound signal and its spectrum and students can visually see how the frequencies it contains are spread.