Undeniably omnipresent in our everyday lives, electronic signal compression is a classical example that illustrates the ubiquity of mathematics in high-end technology and sciences. When dealing with piles of files, it is essential that each file takes up as little storage space as possible while maintaining quality. The cloud-based--available…

Context is what makes mathematical modeling tasks different from more traditional textbook word problems. Math problems are sometimes stripped of context as they are worked on. For modeling problems, however, context is important for making sense of the mathematics. The task should be brought back to its real-world context as often as possible. In…

The Doppler effect is one of the recurring themes in college and high school classes. In order to contextualize the topic and engage the students in their own learning process, we propose a simple and easily accessible activity, i.e. the analysis of the videos available on the internet by the students. The sound of the engine of the vehicle…

We present a simple and accurate experiment to obtain the speed of sound in air using a conventional speaker and a microphone connected to a computer. A free open source digital audio editor and recording computer software application allows determination of the time-of-flight of the wave for different distances, from which the speed of sound is…

My unit on sound and waves is embedded within a long-term project in which my high school students construct a musical instrument out of common materials. The unit culminates with a performance assessment: students play the first four measures of "Somewhere Over the Rainbow"--chosen because of the octave interval of the first two notes--in the key…

Most homes in developed countries have a sophisticated data acquisition board, namely the PC sound board. Designed to be able to reproduce CD-quality stereo sound, it must have a sampling rate of at least 44 kHz and have very accurate timing between the two stereo channels. With a very simple adaptation of a pair of regular PC microphones, a…