Sound Quality and Applications

Music vs. Noise Music –sounds that have a pleasing quality, a definite identifiable pitch, and rhythm –musical instruments use standing waves to produce sound.

–Types of musical instruments percussion (drums, bells, cymbals) – vibrations of membranes or metal stringed (guitars, violins) - vibrations of strings woodwind and brass (flutes, pipe organs, trombones, clarinet) – vibrations of air columns –many instruments sound better and louder when two objects are vibrating at the same frequency; this is called resonance example: both the guitar strings and body vibrate

Noise –sounds that have no pleasing quality, no identifiable pitch, and no relationship between high and low pitches –when noise reaches a level that cause pain or stress it becomes noise pollution

SONAR –uses ultrasonic waves in a system called SOund Navigation And Ranging –determines distance by the time it takes sound to bounce back; formula is d = v · t –Uses of SONAR map the ocean floor military Applications of Sound

Bats and Whales –send out ultrasonic waves that bounce back to locate objects just like SONAR

–Use ultrasound waves to create sonograms very high frequencies (1-15 million Hz) sound travels at different speeds through materials with different densities (bone- high, tissue-low density) used in medical facilities to get a picture the human structure, including a fetus that is growing can even be concentrated to destroy bad tissue Medical