5. Doppler Effect: the change in frequency that occurs when a source of sound is moving relative to the listener Siren on an ambulance
6. Music: group of sounds that have deliberately been produced to create a regular pattern
7. Natural Frequencies: frequencies at which an object will vibrate when struck or disturbed A gong will vibrate and produce a loud noise based on how hard you strike it.
8. Resonance: occurs when an object is made to vibrate at its natural frequencies by absorbing energy from a sound wave or another object vibrating at those frequencies If you take two guitars both tuned the same and place them to where they’re sitting side by side, when you pluck the A string on one guitar you will hear the A string on the other guitar also start to vibrate.
9. Fundamental Frequency: lowest frequency produced by a vibrating object Your vocal cords are able to produce a low frequency sound, called whispering.