Electronic Resources

Focused resources (by topic)

Vibrations

• In Paint Can Oscillator, paper is run in front of an oscillating spray paint can. The video clearly connects simple harmonic motion to its position-time graph. (0:50 youTube video by MIT Physics Demonstration group, accessed February 2018).
• This animation shows a paper dragged past an oscillating pencil, similar to MIT’s Paint Can Oscillator above. (0:40 youTube by Alexander C, accessed February 2018)
• The complex motion of two springs and two masses is the result of the combination (sum, really) of two simple harmonic oscillators (0:26 youTube video by Mohamad Hassoun, accessed March 2018).

Sound needs a medium

• Air is pumped out of a bell jar covering a noisemaker (a drumming toy monkey) to show the role air plays in the propagation of sound. (2:05 youTube video by UNSW PhysClips project, accessed February 2018).

Speed of sound (time of flight, d=vt)

• A high school class uses echoes to measure the speed of sound in air. The teacher shows how to use distance and time measurements to find the speed of sound. (4:55 YouTube video submitted by Bruce Yeaney, accessed April 2018).
• The narrator shows how to measure the speed of sound in air on a cold day using a video camera and editing software.  (5:12 YouTube video posted by ScienceOnline, accessed May 2018).
• You can see how quickly sound travels. A line of people claps in time with a beat they hear. Then the same people respond to a beat they see, so that you can see that there’s a difference between light and sound. (1:08 YouTube video posted by Exploratorium Teacher Institute, accessed April 2018).
• A teacher measures the speed of sound using echoes. Equipment includes a microphone, Audacity, a tube and a ruler. The microphone and Audacity take the place of a stopwatch. (5:32 YouTube video posted by Kamal Wafi, accessed April 2018).

Wave model of sound

• Sound of a Clap shows Schlieren photography of actual sounds. Video explains how video was shot and what it means. (2:31 youTube video by Skunk Bear NPR, accessed February 2018)
• Dan Russell’s website has a page with animations of L- and T-waves, showing the motion of the particles and the motion of the waves. (Accessed March 2018)
• PhET’s Sound (an interactive Java simulation) shows how wave patterns in air near a loudspeaker. Users can vary the frequency and amplitude of the source and view changes to the wave pattern. A “Measure” tab allows students to explore the math. (Accessed March 2018)
• Short video shows difference between L- and T-waves on a spring. (0:24 youTube video by The Animations for Physics and Astronomy project, accessed March 2018).
• Falstad’s WebGL Ripple Tank Simulator is a very flexible playground for exploring the properties of waves. (accessed January 2020).

Hearing and perception

• This web page summarizes connections between vibration properties and human perceptions of sound characteristics- that is, the connections between (amplitude, frequency, spectral content, time envelope) and (loudness, frequency, timbre). (UNSW PhysClips project, accessed February 2018)
• The hearing test at UNSW’s website shows how loudness perception depends on frequency. The page includes FAQ on hearing tests, loudness and information on equal loudness contours. (UNSW Physics, accessed February 2018)

Spectrograms, timbre, overtones and related

• In the Bird Hero Game, you try to match the recordings of bird songs with their spectrograms. Basic game takes less than ten minutes. There’s an advanced level, if you’re thirsting for more. (Cornell Ornithology Lab,  accessed February 2018)
• There are lots of youTube videos of musical recordings coupled with not-quite-spectrograms that plot pitch (musical note, really) versus time. Some of my favorites are Bach’s Little Fugue in g minor (3:45 min by Stephen Malinowski, accessed February 2018) and Liszt’s Hungarian Rhapsody Nr. 2 (8:58 min by Andy Fillebrown, accessed February 2018) and a whimsical Classical Music Mashup (6:08 min by Grant Woolard, accessed February 2018)
• This  explores the connections between timbre and sound graphs. The same note (C128) is played by many instrument while multiple graphs are created in real time. A spectrogram, time-domain graph and live FFT of each sound are shown as the sound plays. The video uses Overtone Analyzer by Sygyt Software. (2:05 youTube by What Music Really Is, accessed March 2018)
• Anna-Maria Hefele explains overtone singing with Overtone Analyzer. This youTube video (9:15 min by Anna Maria Hefele, accessed March 2018) breaks a single musical note into its many frequency components.

Resonance

• In this BBC promo, Helen Czerny explains resonance with conkers tied on a string. (2:13 youTube, Helen Czerny, accessed November 2018: https://youtu.be/yFsgu3ClqHo).
• Physicists explain why the famous Tacoma Narrows bridge collapse was not resonance in this youTube video (1:54 min by MinutePhysics, Perimeter Institute, accessed March 2018). Several edits of newsreel footage of the bridge disaster from 1940 are also on youTube. Another youTube video (0:39 by EuroNews, accessed March 2018) shows aerostatic flutter on a bridge in Russia in 2010.
• Students excite different resonances in a wooden foot bridge resonate in this youTube video (5:00 min by Bob Barrett, accessed March 2018).
• In Sound: An interactive ebook, Forinash claims that this helicopter failure (0:37 youTube posted by squorch, accessed March 2018) was due to ground resonance.
• Resonance cart demo shows that different parts vibrate at different frequencies (0:56 youTube posted by UCIPHO from U.C. Irvine, accessed March 2018). Another resonance cart demo, with fancier equipment and Greek subtitles (3:42 youTube by ScienceForAll).
• This excerpt from MythBusters (3:08 youTube posted by PsiTechs, accessed March 2018) shows how to break a wine glass with sound. A key step that many youTube videos omit is tapping the glass (and listening to or recording the resulting sound) to find the proper pitch to sing at to break the glass.
• High school physics teacher shows coupled pendula as an example of resonance (3:25 youTube by Bruce Yeany, accessed March 2018).
• Coupled oscillators show how energy can be transferred from one type of motion to another at the resonant frequency. (2:54 youTube by Bruce Yeaney, accessed March 2018).
• What’s up with noises?” is a breakneck speed overview of a variety of resonance topics including strings, the workings of the ear and the creation of complex tones. (12:48 youTube by Vi Hart, accessed March 2018).
• This well-done student project explains ocarinas and Helmholtz resonance. The numerical analysis in the second half of the video is slightly above the math level of this book. (4:36 youTube by Sydney Jacobsen).
• Lee Hite’s wind chimes website is a treasure trove of information for anyone interested in making their own wind chimes. (accessed June 2018)
• Alvin Lucier’s “I am sitting in a room” is a classic piece of performance art that shows how the resonant frequencies of a room can transform the human voice. Over the course of 45 minutes, the same short paragraph is played into a room and recorded. The recording gets played into the room and recorded and so on… (accessed October 2018)

Standing waves (strings)

• Two students demonstrate different modes of standing waves on a string using a frequency generator. (3:21 youTube video by Ondrea Glover and Stephanie Calderon, accessed August 2018)
• Animated gifs of standing waves patterns for strings are available on Wikimedia Commons (accessed August 2018) and on Dan Russell’s Standing Waves webpage (accessed August 2018). The PhysClips site has a similar resource as a shockwave file. PhysClips’ movie shows n=1 beyond the end of the string (in light color).

Standing waves (in air columns)

• Animated gifs of standing waves patterns in an air column are available on Dan Russell’s Standing Waves webpage (accessed August 2018). Dan Russell’s page clearly shows the connection among pressure-position, displacement-position graphs and mock-ups of molecular motion.

Interference and superposition

• The Original Two Slit Experiment explores the ideas and history behind Thomas Young’s groundbreaking demo/experiment that shows superposition of light waves. Roughly 4:20 into the video, the narrator shows two source interference using ripples on a pond. (7:39 YouTube posted by Veritasium, accessed May 2018).
• PhET’s Sound is an interactive Java applet that allows users to explore and visualize multiple aspects of sound waves, including two source interference. (PhET Interactive Simulations, accessed May 2018).
• PopsicleSticks shows shows the principle of of superposition at a very basic level. (0:39 YouTube posted by David Abbott, accessed May 2018).
• Superposition of Waves (0:08 YouTube posted by physics007aniimations, accessed May 2018) shows two pulses as they pass through each other.
• SuperpositionDesmos shows the basic math of superposition using two examples. (3:36 YouTube posted by David Abbott, accessed May 2018)
• Argonne’s acoustic levitation video shows how you can create standing waves using two speakers pointed at each other. (1:02 YouTube posted by Argonne National Lab, accessed May 2018).
• Acoustic levitation can also be achieved by reflecting a traveling wave back on itself, but only if the distance between speaker and reflecting surface is just right. Video includes Schlieren photography of the standing wave.  (4:33 YouTube posted by Harvard Natural Science Lecture Demonstrations, accessed May 2018).
• Two traveling waves interfere to form a standing wave. This animation shows each of the traveling waves separately as well as the resulting standing wave. Users can pause, play and zoom the animation. (Desmos animation posted by David Abbott, accessed May 2018).
• This beats visualizer shows how two slightly different frequencies combine to create beats. Users can adjust the frequency and amplitude of one of the sources and see the resulting waveform. (Desmos animation posted by David Abbott, accessed May 2018).
• Short Shockwave presentation on Beats. Link goes directly to download; parent directory is not directly accessible. (David Harrison, accessed May 2018).
• Lecture notes on beats and combination tones; part of a collection of notes for MUS150 at Stanford University.  (Gary Scavone 1999, accessed May 2018).
• Interactive Moire pattern visualizer allows students to explore the visual effect of overlapping regions of lines with different spacing. (Desmos animation posted by David Abbott, accessed May 2018).
• CenterPoint Audio has a simplistic, but informative webpage on how noise-canceling headphones work.  (webpage accessed July 2018).

Websites, eBooks, etc.

• PhysClips Project at the University of New South Wales is collection of educational materials for intro physics. Volume II covers Waves and Sound. Intended audience is high school and intro algebra-based physics students (and teachers). Most materials are at the level of this book. Some animations require Flash. (accessed February 2018)
• The Khan Academy videos on Sound are aimed at high school and intro algebra-based physics students. Most are at the level of this book. There are about twenty videos in the series, each about four minutes long. (accessed February 2018)
• World through Sound is a series of twelve articles by Andrew Pyzdek, each covering an important topic. Articles are purely conceptual, but the physics insights are pretty deep. (hosted by Acoustics Today, accessed March 2018).
• Sound: An interactive ebook is a short (free) online text written at the college physics level. The book includes dynamic material including videos and interactive simulations. (Kyle Forinash and Wolfgang Christian, accessed March 2018)
• Jennifer Berg’s online book Digital Sound and Music is written for those interested in music recording careers. The math level is mostly at the college physics level. Physics is in the first four chapters; applications follow. The text has lots of interactive features interspersed throughout- MATLAB exercises, Max demos (Max is a graphical program environment), programming exercises (C++ and Java), practical exercises, and video tutorials.
• Dan Russell’s Acoustics and Vibration Animations website  is a collection of animations with explanatory text. It is particularly useful for viewing models of waves. The math level of the pages on Dan Russell’s website varies from high school to advanced undergrad. (accessed April 2018)
• Hyperphysics is a collection of static web pages on basic physics topics, including a section on Sound and Hearing. Navigation through this website can be tricky. Topics are at the level of college physics. (accessed April 2018)
• Course notes for Gary Scavone’s course MUS150: Musical Acoustics at Stanford. Level is at or above college physics.
• Sound is an ebook about aimed at high school students produced by the NDT Education Center. (accessed July 2018)

Random things

• Bart Hopkin is an inventor specializing in odd, mostly acoustical musical instruments. Hopkin’s site includes an Instrumentarium (with links to youTube demos of many of his creations) and Writings which focus on the physics and music theory behind his art.
• http://www.sonicwonders.org/ is a compendium of places to go where hearing is an important part of the experience.

Simulations

• PhET’s Sound and Waves page has a cluster of interactive simulations.
• Sound (Java) shows how air reacts to a loudspeaker. Users can vary the frequency and amplitude of the source and view changes to the wave pattern. Additional tabs allow students to “measure” distances and times, view two source interference and explore the classic bell jar demo. (Physics Education Technology at Colorado University, accessed March 2018).
• Waves Intro (HTML5) holds three sims in one- a ripple tank, a sound and light- that explore traveling waves. Measuring tools (ruler, stopwatch, etc) are provided.

Software

• Audacity is freeware designed for making and editing multi-track recordings. Though really designed with musicians in mind, Audacity includes graphing, analysis and synthesis tools that are useful for an introduction to sound class. Audacity works on PC, Linux and Mac platforms, but not mobile devices.
• Logger Pro is educational software by Vernier Software and Technology designed for computer-based data acquisition. This software is only useful for students in classrooms already equipped with Vernier’s hardware and software. Used in conjunction with Vernier’s Go Direct Sound probe or Vernier’s Microphone, Logger Pro is a powerful tool for producing and analyzing graphs of sound. Unfortunately, Vernier’s (free) Logger Lite software does not support FFTs or other features useful for analyzing sounds.