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Hearing and balance
Writing and alphabets
8 other sections not shown
alphabet amplifier animals anode antenna atom band beam bounce brain Brass instruments cable called camera carrier wave cassette cathode coil of wire color column of air communication diaphragm distance drum ear-drum Earth echo echolocation electric current electromagnetic wave Eustachian tube free electrons frequency harmonics hear holes human inside instrument invented ionosphere language large number layer letters light lines machine magnetic messages metal microphone mouthpiece move musical n-p-n transistor n-type n-type semiconductor negative charge nerve nervous system orbit p-n-p transistor paper pass percussion instruments pheromone picture piece positive printing produced radio waves receiver recording head satellite scanned screen scribes semiconductor sent signs silicon sound waves space speed spinal cord string symbols telephone television thin tiny transistor transmitted triode tube ultrasound vacuum varying electrical signals vibrate video cassette recorder video head vocal cords words