Chapter 10 Test Flashcards
What factors affect the speed of sound?
the mediums:
-density
-elasticity
-composition
-temperature
-state of matter (solid, liquid, gas)
What are the three parts of the ear?
outer ear
middle ear
inner ear
What are the three ear bones?
malleus (hammer)
incus (anvil)
stapes (stirrup)
What is intensity?
the amount of energy transferred by a sound wave through a certain area each second
What is loudness?
the human perception of sound intensity
What is frequency?
frequency is the measure of how many wavelengths pass a particular point each second
What is pitch?
Pitch is the human perception of the frequency of a sound
What is acoustics
the study of sound
What is echo
a reflection of sound that arrives at the listener with a delay after the direct sound
what is echolocation
the process of locating objects by emitting sounds and then interpreting the sound waves that are reflected from those objects
What does SONAR stand for
SOund Navigation And Ranging
why are sonars used
to locate objects or determine distance
what is a sonar
a system that uses the reflection of underwater ultrasounds to locate objects or determine distances
What is the normal frequency range of human hearing for young adults?
20Hz to 20,000Hz
What are the factors needed for a room to cause an echo?
- the time gap between the original sound and the reflected sound mus be at least 0.1 seconds
- the distance between the original sound and the nearest wall must be at least 17.2 meters
- minimal sound absorbing materials
What are some uses for ultrasound?
-examine baby during pregnancy
-see organs in body
-break up kidney stones
-treat injury to soft tissue like muscle
What is the speed of sound in air (0C)?
330 m/s
What is the speed of sound in air (20C)?
340 m/s
What is the speed of sound in cork
500 m/s
What is the speed of sound in water (0C)?
1400 m/s
What is the speed of sound in water (20C)?
1500 m/s
What is the speed of sound in copper?
3600 m/s
What is the speed of sound in bone?
4000 m/s
What is the speed of sound in steel?
5800 m/s
What receives the reflected sonar signal?
a hydrophone
Why would someone use ultrasound instead of x-ray?
ultrasounds show movement
x-rays are bad for you
What is persistence of hearing?
when you make a sound you are going to hear it for 0.1 seconds
Sound waves are ____ waves
compressional/longitudinal
mechanical
Sound waves travel by the process of ___
conduction
What is amplitude related to on a longitudinal wave?
the density of the particles in the compressions and rarefactions
sound waves with greater amplitudes carry ___ energy and therefore are ___
more
louder
the intensity of a sound wave ___ as the wave spreads out from the source of the sound. Why?
decreases
-energy spreads out as the wave does
-sound energy converts to other forms
What do sound waves’ energy usually convert to
thermal energy
What materials are good at converting sound energy to other forms of energy?
soft thick curtains
What is the unit used to measure sound intensity?
decibel (dB)
What is intensity directly related to?
energy and loudness
The frequency of a sound wave is directly related to ___
the pitch of a sound
high pitch sound = ___ frequency
high
What happens to the range of sound wave frequencies that you can hear as you age?
it decreases
waves with frequencies above 20,000Hz are called ____
ultrasonic (ultrasound)
waves with frequencies below 20Hz are called ____
Infrasonic (infrasound)
What is the doppler effect
the change in the frequency of a wave due to relative motion of the wave source to the observer
What are some different uses of sound waves?
medicine
fishing boats (detect schools of fish)
find sunken ships
building music halls and theaters
sound proofing rooms
finding oil or different minerals in the earth
What uses echolocation?
bats and dolphins
Ultrasound is sound with a frequency above ___Hz
20,000
Why does sound travels faster in higher temperature mediums?
when the temperature of the medium increases, the particles in the medium move faster so they collide more often causing the sound waves to travel faster
How does the ear work?
- Outer ear funnels sound into the eardrum where it vibrates
- In the middle ear the vibrations cause the lever system made out of the malleus, incus, and stapes to amplify the sound waves
- the stirrup vibrates the oval window
- In the inner ear the vibrations from the oval window move the fluid in the cochlea (structure filled with liquid and tiny hairs) which moves the tiny hairs that are connected to the auditory nerve that converts the vibrations into electrical impulses
