Harmonic structure, also known as timbre.
if i made ear defenders i would : Use foam because - it will absorb the sound Use rubber because - it has a lot of air bubbles in it. Sound takes a long time to travel through gases like air . Also some of the sound may reflect off the rubber. airpoo Vacuums, because sound travels best through air and there would be no air to travel through. And use cotton wool. : )
The sound is introduced into the narrow end of the megaphone, by holding it up to the face and speaking into it, and the sound waves radiate out the wide end. The megaphone increases the volume of sound by increasing the acoustic impedance seen by the vocal cords, matching the impedance of the vocal cords to the air, so that more sound power is radiated. It also serves to direct the sound waves in the direction the horn is pointing. It somewhat distorts the sound of the voice because the frequency response of the megaphone is greater at higher sound frequencies.
Sound of electricity
Something that sounds like the word that represents it. For instance flip flops are an onomatopoeia because when you walk in them they make a sound that sounds like flip flop.
A circuited switch, which operates with sound of clapping hands or something similar; ie. the switch comes to 'on' position when clapped once or twice, and to 'off' position when again clapped once or twice (depends on circuit design)