Sound

Sound

1. Sound: Is a form of energy.

2. Sound requires a medium to travel.

   • Sound travels because the vibrations are passed from molecule to molecule, therefore sound requires a medium to travel through.
     • Examples: Solid, Liquid, Gas

3. The Speed of Sound

   • The Speed of Sound in air is about 340m/s.
     • This can change slightly if the temperature or air pressure changes.
   • The Speed of Sound in water is slower than in air.
   • Sound Waves travel fastest through Solids and slowest through Gases. (The Particles are closer together in a solid which helps the vibrations travel faster than a gas, as gas molecules are spread out).

4. Reflected Sound (Echo)

   • When Sound meets are hard, flat surface, the sound wave is reflected back from the surface.This is what we call an Echo.
   • Echo: Is a Reflected Sound

5. The Human Ear and Loud Sounds

   • The scientific name for the loudness of a sound is the Sound Intensity Level. Here we call this Sound Level. Sound Level is measured in Decibels.

6. Ear Protection

   • 120 Decibles is the loudest sound level you should listen to.
   • 120 Decibels will case pain in your ear and most likely will result in permanent ear damage.
   • Any sound above 70 Decibels can cause harm to your ear, it is for this reason that hearing protection is recommended for loud sounds.

7. Noise and Effects

   • Noise: A noise is any unwanted sound.What one person might consider noise another person might not.
   • Noise can cause hearing problems. Three effects of Noise:
     • 1)Headaches 2)Nausea 3)Deafness
   • Three ways to reduce the effects of Noise:
     • 1)Ear Protectors 2)Double Glazing 3)Putting noisy machinery in insulated rooms.