Group+4


 * 17.4 Soun****d and Hearin****g**

//**Properties of Sound Waves** Intensity and Lo////udness//
 * Loudness is a physical response to the intensity of sound and is modified by physical factors.
 * Intensity is the rate wave energy flow through an area
 * when loudness increases, intensity increases
 * when loudness decreases, intensity decreases
 * sound intensities are measured in decibels (dB)
 * Decibles are based off powers of 10

//Frequency and Pitch//media type="custom" key="5865471" width="180" height="180" //Speed//
 * Frequency of sound as you perceive it.
 * Frequency is how fast a source is vibrating
 * Pitch depends on age and health of your ears
 * examples: Trumpet and French horn
 * if their is high frequency then their is high pitch
 * if their is low frequency then their is low pitch
 * at 20 degrees celcius the speed of sound travels at 342 m/s
 * sound travels fastest in solids, slower in liquids, and slowest in gases

//**Uses**// //Ultrasound// //Doppler Eff////ect// //Music// Hearing with Ears
 * is used in a variety of applications including sonar and ultrasound imagery
 * example: to look at babies or your heart
 * Sonar helps determine the distance to an object underwater
 * it is calculated using the speed of sound in water and amount of time an echo is
 * doppler effect is a sound frequency caused by a movement of the sound source, motion of listener, or both
 * Close=Higher pitch, Farther=Lower pitch
 * most instuments have different pitches by changing the frequency
 * resonance is the response of a standing wave to another at the same frequency
 * the outer ear gathers sound to the middle ear, which then amplifies the vibrations. Then uses ear nerve endings to the brain.