properties of sound 16 2 l.
Skip this Video
Loading SlideShow in 5 Seconds..
Properties of Sound 16.2 PowerPoint Presentation
Download Presentation
Properties of Sound 16.2

Loading in 2 Seconds...

play fullscreen
1 / 15

Properties of Sound 16.2 - PowerPoint PPT Presentation

  • Uploaded on

Properties of Sound 16.2. Pages 546- 551. Loudness. Loudness describes your perception of the energy of sound It describes what you hear The closer you are to the sound, the louder it is Loudness of a sound depends on two things: 1. The amount of energy it takes to make the sound

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Properties of Sound 16.2' - nikki

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
  • Loudness describes your perception of the energy of sound
    • It describes what you hear
  • The closer you are to the sound, the louder it is
  • Loudness of a sound depends on two things:
    • 1. The amount of energy it takes to make the sound
    • 2. The distance from the source of the sound
energy of a sound source
Energy of a Sound Source
  • The greater the energy used to make a sound, the louder the sound
    • Example: Playing a guitar
      • When you use more energy to pull the strings of the guitar the louder the noise produced by the guitar is
  • The more energy you use, the larger the amplitude
  • The larger the amplitude produces a louder sound
distance from a sound source
Distance From a Sound Source
  • Loudness increases the closer you are to a sound source
    • Close to the sound source, the sound waves cover a small area
    • As waves travel away from the sound source, it covers more area
  • The total energy of the wave stays the same whether it’s close to the source or far away from it
    • The closer the sound wave is to its source, the more energy it has in a given area
distance from a sound source5
Distance From a Sound Source
  • The amount of energy a sound wave carries per second through a unit area is its Intensity
  • A sound wave of greater intensity sounds louder
  • When you move away from the sound source, loudness decreases, because the intensity decreases
measuring loudness
Measuring Loudness
  • Loudness is measured using the unit called the decibel (db)
  • Each 10-db increase in loudness represents a tenfold increase in the intensity of the sound
    • Example:
      • soft music at 30-db sounds 10x louder than a 20-db whisper
      • Soft music at 30-db sounds 100x louder than a 10-db sound of rustling leaves
  • Sounds louder than 100-db can cause damage to your ears, especially if you listen to those sounds for long periods of time
  • Pitch is a description of how high or low the sounds seems to a person
  • The pitch of a sound that you hear depends on the frequency of the sound wave
pitch and frequency
Pitch and Frequency
  • Sound waves with a high frequency have a high pitch and sound waves with a low frequency have a low pitch
  • Most people can hear sound with frequencies between 20Hz and 20,000Hz
    • Sound waves with frequencies above the normal human range of hearing are called ultrasound
    • Sound waves with frequencies below the normal human range of hearing are called infrasound
    • People cannot hear infrasound or ultrasound waves
changing pitch
Changing Pitch
  • Lungs: Air From the lungs rushes up the trachea
  • Vocal Cords: which are located in your voice box, or larynx vibrate as air rushes pass them
  • Sound: Sound waves produced by the vibrating vocal cords come out through the mouth
changing pitch11
Changing Pitch
  • Pitch is an important property of music
  • To change pitch, you use the muscles in your throat to stretch and relax your vocal cords
    • When your vocal cords stretch they vibrate more quickly, which creates higher-frequency sound waves with a higher pitch
    • When you vocal cords relax they vibrate slower, which creates lower-frequency sound waves with a lower pitch
  • Musical instruments can also change pitch!
the doppler effect
The Doppler Effect
  • The change in frequency of a wave as its source moves in relation to an observer is called the Doppler effect
  • If the waves are sound waves, the change in frequency is heard as a change in pitch
what causes the doppler effect
What Causes the Doppler Effect?
  • When a sound source moves, the frequency of the waves changes because the motion of the source adds to the motion of the waves
    • When a source moves towards a listener, the frequency of the waves is higher than it would be if the source were stationary
doppler effect example
Doppler Effect Example:
  • Observer 1: Hears a lower pitch than the driver
  • Observer 2: Hears a higher pitch than the driver
  • Driver: Hears the normal pitch
what causes shock waves
What Causes Shock Waves?
  • A shock wave forms as the sound waves overlap
  • The shock wave releases a huge amount of energy
  • People nearby hear a loud noise called a sonic boom when the shock wave passes by them
    • Example: when a plane moves faster than the speed of sound, a shock wave is produced