It has now been over 100 years since Heinrich Barkhausen published his description of a crackling sound heard when a piece of iron is magnetized inside of a coil wired to a set of headphones, and this phenomenon provided evidence for the theory of magnetic domains. Traditionally, this effect is performed as a demonstration by connecting the coil…

The integration of physics, music, and mathematics has long been used to increase students' interest and motivation in these subjects. For example, previous articles in this journal have shown how to teach physical concepts in a musical context, use a smartphone to check the resonant frequencies of whistles, use a smartphone to examine the spectra…

We present a simple experiment that allows us to demonstrate graphically that the intensity of sound waves is proportional to the square of their amplitude, a result that is theoretically analyzed in any introductory wave course but rarely demonstrated empirically. To achieve our goal, we use an audio signal generator that, when connected to a…

Podcasts offer a unique tool in making science learning informative, engaging, and entertaining. They provide an excellent way to incorporate storytelling in science instruction. Podcasts can be accessed easily and free of cost on any internet-enabled device. Recording podcasts is also easy and inexpensive, making them useful to record lesson…

In recent years, with the more powerful functions of smartphones, the use of sensors integrated by mobile phones as an auxiliary tool for physical experiment teaching has become more popular. Combined with the related mobile phone apps, people easily can develop and expand the physical experiment contents of mechanics, optics, acoustic phenomena,…

We propose an easy experiment that allows students to determine the speed of sound through a simple time-of-flight measurement using two smartphones. The concept of using the sensors in mobile phones for physics experiments has become a well-known option for science teachers. Since these devices are readily available to most students and teachers,…

The labs presented here build on a simple speed of sound activity and models medical ultrasound imaging by demonstrating how multiple reflections propagate in a closed system. A short sound pulse is emitted into a pipe that is closed at one end and contains one or more partially reflecting surfaces within the pipe. The variety of reflections and…

Inexpensive alternatives to a number of classic introductory physics sound laboratories are presented including interference phenomena, resonance conditions, and frequency shifts. These can be created using earbuds, economical supplies such as Giant Pixie Stix® wrappers, and free software available for PCs and mobile devices. We describe two…

Learning and understanding physics requires more than studying physics texts. It requires doing physics. Doing research is a key opportunity for students to connect physical principles with their everyday experience. A powerful way to introduce students to research and technique is through subjects in which they might find interest. Presented is…

While I was co-teaching an introductory course in musical acoustics a few years ago, our class investigated several pieces of equipment designed for audio purposes. One piece of such equipment was a pair of noise-canceling headphones. Our students were curious as to how these devices were in eliminating background noise and whether they indeed…

Minds-On Audio-Guided Activities (MAGA) are podcast-delivered instruction designed to facilitate learning through all-body experiments. Instruction by MAGA has undergone preliminary testing in an introductory physics course at Central Michigan University. Topics are currently focused on mechanics and range from discovering the differences between…

Signal generators, oscilloscopes, and data acquisition (DAQ) systems are standard components of the modern experimental physics laboratory. The sound card, a built-in component in the ubiquitous personal computer, can be utilized for all three of these tasks and offers an attractive option for labs in developing countries such as…

Use of a microphone attached to a computer to capture musical sounds and software to display their waveforms and harmonic spectra has become somewhat commonplace. A recent article in "The Physics Teacher" aptly demonstrated the use of MacScope in just such a manner as a way to teach Fourier analysis. A logical continuation of this project is to…

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…

Potato cannon velocity can be measured with a digitized microphone signal. A microphone is attached to the potato cannon muzzle, and a potato is fired at an aluminum target about 10 m away. Flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato…