Make a Neuron
Materials: Pipe cleaners, 5 for each project, at least 3 colors. Beads that can just fit over pipe cleaner when folded in two and twisted.
1. Role one pipe cleaner into a ball as the cell body
2. Attach another to the cell body, sticking it through the ball and then twisting the two halves together to make the axon.
3. Similarly, stick several of the same color through the ball at opposite end to make dendrites
4. Place beads over axon to represent myelin sheath
5. Make end of axon into a smaller ball to represent synaptic terminal.
Discuss while making the models what each part does, how many are in the body, and how they convey auditory and balance information.
Make a Model of the Cochlea or Inner Ear
Materials: Playdough, several colors
1. Separate two small balls of Color 1 and one small ball of Color 2.
2. Roll each ball into 3-4" ropes
3. Layer the ropes and coil into shape of cochlea
4. Use a sharp knife to divide along modiolus and relate to a physical model of the cochlea to show the chambers
For older students, have a physical model of the inner ear and let students explore using playdough to craft all of the structures. Point out what each does.
Materials: Mouse ossicles, cleaned and mounted. Ossicle models
1. Focus on asking students if they know where the smallest bones and muscles are located in the body. Show a model of the middle ear. Talk about why you need one. Could even show how this is done in lower vertebrates with just a single bone.
2. Collect some mouse middle ear bones, and clean with bleach. Coordinate with Keith and the ERC to have a small microscope on site. Show students how to use the microscope and image the middle ear bones.
Animal-Ear-Spectrum matching game
Materials: poster board with pictures of various animals (human, dog, dolphin, elephant, bat...), cutouts of the relative inner ear sizes (cochlea specifically) for each animal laminated with velcro on back, cutouts of hearing spectrum for each animal with velcro on back (piano keys with min/max frequencies, adjusted to span # of octaves in spectrum).
1. Ask students if they can guess which animal can hear the highest notes, the lowest notes.
2. Explain the cochlea and hearing spectrum cutouts
3. Ask students to use the velcro and place each cutout with the animals. Rearrange them if any are wrong.
Auricles are for more than earrings
Materials: Putty and model of external ear
1. Use putty to build a/your auricle.
2. Describe which parts are important and why
Cochlear Implant Simulation
Materials: Laptop, headphones, sanitary wipes
Use simulations online or make your own. Filter using different numbers of simulated channels. Have participant guess what is being said (need good over-ear headphones; ambient noise levels may be high). Sanitary wipes available for cleaning headphone cups between use. Mods: pair with video of speaker in a second simulation to see if it is easier to understand.
Materials: cochlear implant model, video of implant concept and someone activating implant for first time
Use a CI device and animation/model to demonstrate how an implant is placed, how it works, and how it helps.
Implement various auditory illusions
See https://www.newscientist.com/article/dn13355-music-special-five-great-auditory-illusions/ for some insights into music-based and perceptual illusions that could be implemented fairly easily.
Materials: Laptop, headphones, sanitary wipes
YouTube demos of this perceptional phenomenon from McGurk and MacDonald (1976) abound. As above, only a few items are needed to pull this one off.
Hair cell activation
Materials: hair dryer, long pipe cleaners, laptop
Show video clip of air pressure waves and hair cell activation in cochlea. Have participants create model hair cells with styrofoam cylinders and pipe cleaners of different lengths. Could rubberband pipe cleaners to show that they move as a unit. Add googley eyes and faces for fun ;-)
Physics of sound demos
Demonstrate Rinne and Weber tests (confirm that you can do this in a loud space).
Demonstrate physics of sound relating resonance with shape of the fork.
Demonstrate sympathetic tuning forks, where resonance from one will excite another (with the same resonance)
Demonstrate transfer of sound (http://www.physicsclassroom.com/class/sound/Lesson-5/Resonance)
Demonstrate resonance and physics of musical instruments
Explain frequency spectrum and spectrograms
Materials: laptop, microphone
Describe how a spectrum analyzer works and correlate to the function of the cochlea. Let participants see their voice using a mic and laptop with real-time analyzer. Explain spectrogram and show spectrograms of bird songs, showing bird and playing audio file that goes with each. Show distinguishing features. Then have a participant match a novel spectrogram with a novel bird song.
Materials: laptop, headphones, sanitary wipes
Use online sources or build scripts of your own to demonstrate sine-wave speech (http://www.lifesci.sussex.ac.uk/home/Chris_Darwin/SWS/). Reveal how well you can understand the sine-wave speech after hearing the original. Compare the spectrograms.