Sound waves are longitudinal Sound can be explained by understanding Speed Intensity and loudness Frequency and pitch Most people hear sound between the frequency of 20Hz and 20000Hz Anatomy of Sound ID: 711787
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Slide1
SoundSlide2
Properties of Sound
Sound waves are longitudinal!
Sound can be explained by understanding:
Speed
Intensity
and loudness
Frequency and pitch
Most people hear sound between the frequency of 20Hz and 20,000Hz. Slide3
Anatomy of Sound
External Ear:
Focus the sound into the ear canal.
Middle Ear:
Amplifies the vibrations.
Inner Ear:
Senses the vibrations and signals the brain.Slide4
Anatomy of Sound
The Middle Ear is made up of 3 tiny bones known as the hammer (
malleus
), anvil (
incus
) and stirrup (stapes). Slide5
A. Speed
The speed of sound (in dry air at 20°C) is 342m/s.
The speed of sound varies with the temperature and phase of matter it is traveling through.
Most fast is solids
slowest in gasesSlide6
B. Intensity and Loudness
Intensity refers to the rate at which sound waves travel in a given area.
Depends upon the amplitude of the sound waves and the distance from the source.
Loudness is a subjective term. It is the physical response to sound intensity. Depends upon a person’s health, age, etc. Slide7
B. Intensity and Loudness
Intensity is measured in
Bels
(decibels, dB). The scale is more logarithmic
0dB can barely be heard.
20dB is 100 times more power than 0dB.Slide8
C. Frequency and Pitch
Sound frequency depends upon how fast the source of the sound is vibrating.
Longer waves produce lower sounds frequency
Shorter waves produce high frequency
Pitch is a person’s perception of sounds frequency. (Subjective)
High pitch = high frequency
Low pitch = low frequencySlide9
Ultrasound
Ultrasound waves are used in medicine and sonar techniques.
Ultrasound can be used to construct images of internal structures. Slide10
D. The Doppler Effect
The Doppler Effect explains how the pitch of a sound can change as it passes a person or point.
It is the change in sounds frequency caused by motion of the sounds source, motion of the listener, or both. Slide11
As a sound source approaches the frequency increases. As the source moves away the frequency drops.