a) Eidophone
b) Long string instrument
II. BONE CONDUCTION
a). Bone Amplifier/Headphones-
Take a wire coat hanger and tie a single length of thread to each corner, creating a loop. Hang the thread loop over your head so that the hanger is dangling upside-down under your chin and swinging freely. Take the lengths of thread that are hanging by your ears and use your index fingers to gently press the thread against the inside of your ear (as though you are sticking your fingers in your ears to block sound). Make sure the thread is making good contact with the inside of your ears and have a friend gently tap the hanging coat hanger with a pencil or other piece of wood or metal. Make a silent concert!
Bone conduction fans and hearing trumpets:
d). Tune a guitar in a noisy room by biting it!
{{{{{{c). Tape recorders-
Your voice sounds higher to you because you are used to hearing yourself through your own body’s bone conduction, which supports low frequencies. (Find a source and activity for this).}}}}
II. RESONANCES OF MACHINES, OBJECTS, AND SPACES. AUDIBLE INFRASTRUCTURE
Modes of vibration in a wine glass:
Listen:Filtering the resonances of a refrigerator with a coffee can.
-Filtered resonances of a ice-rink resurfacer (recording by Jean-François Laporte).
d). Making hand baffles or “ears” to change what part of the spectrum we are listening to. Just cupping your hands around your ears can make the sound about 10 dB louder! Small ears highlight high frequencies, big ears bring out the bass. The original ‘topophone’ (see below) was developed to help localize sounds at sea by creating a larger interaural time difference as well as amplifying the sounds.
Spectrums of objects
e). Tuned listening tubes (that can then later be percussively excited to make notes!)
glass gamelan
c). Exploring spectrums of machines:
-Listening to AC current (60hz!) and the music of engines (can we bring in or consult with an engineer on this?).
f). Clock chimes and other mechanical noise-makers.
These are mechanically very much like the coil of a speaker magnet! (with the round metal cups and bases acting as an amplifier).
g). Ordinary objects in motion: Forks, cutlery, bowls, bars, tines, clutter, suspended by threads, set on bubble wrap, placed on felt, suspended by thread, attached to walls etc.
h). Construction of thumb pianos and other metallophones.
IV. BODY RESONANCES
Bone conduction houses and furniture.
VI. SENSORS
a). A simple electro-magnet
Piezo microphones: crystals! (what makes them tick?) Reversing flow…makes a speaker!
VII. AMPLIFICATION
Listening:
Baby Vultures using the resonance of a tree trunk as an amplifier to scare off predators.
Try: Tuning fork baffles.
-‘If a tuning fork is struck and slowly passed through a slot in a sheet of paper, the loudness increases noticeably as each tine passes through the slot. The paper, acting as a crude baffle, partially blocks the short-circuit path from one side of the vibrating tine to the other. The same baffle experiment can be done with a small speaker (2-3"), being so small it has very little support for low end frequencies (which have big wavelengths) and is therefore distorted. This can be changed by placing the speaker against a piece of plywood with an appropriate hole.’ P. 430 Rossing
a). Singing into glass jars, metal bowls, and room corners to find the resonances. Finding all of the resonances of the space by singing.
Electromagnets continued-Hannah Perner Wilson’s fabric speaker coils
-Use vintage paper cutting techniques to make various shapes of speaker cones that we can attach to the piezos we soldered, etc.
VIII. FINI
a). Instruments and home-made microphones are plugged into amplification systems (both acoustic and electronic), and a concert is played!
Projects:
Bone Conduction:
Long String Instrument
Adapted from Ellen Fullman's work.
Inspired by Hannah Perner Wilson and ***
Chladni and Eidophone Singing
Bone Conduction:
Table
Hangers