The Nature of Sound
What is the term for a material that stretches or distorts and returns to it's shape?
Elastic
As the frequency of sound increases, so does the sounds ______________.
a) loudness
b) intensity
c) decibel
d) pitch
d) pitch
Elastic materials, such as guitar strings, vibrate at what type of frequency?
Natural Frequency
What sound waves can dogs hear that humans can't?
Ultrasonic Waves
Why does sound travel faster through a solid than a liquid?
The particles in a solid are closer together than in a liquid, colliding more with each other (more vibrations) and producing greater sound.
Which material does sound travel fastest through?
a) air
b) steel
c) water
d) helium
b) steel
The rate at which energy passes through a specific area is called...?
a) pitch
b) intensity
c) loudness
d)decibel
b) intensity
What is the lowest frequency of a vibrating object called?
Fundamental Frequency
What is the range of frequencies humans can hear?
20 Hertz -20,000 Hertz
When two tones with slightly different frequencies occur at the same time, they produce a variation in loudness known as _______________.
beats
What kind of wave is a sound wave?
a) transversal
b) electromagnetic
c) compressional
d) none of the above
c) compressional
This occurs when there is a change in frequency when a sound-emitting object moves relative to the listener.
In other words, a moving source or a moving listener produces what?
Doppler Effect
What do we call sounds that vibrate at several different higher frequencies at the same time?
Overtones
Which of the three sections of the ear transfers vibrations into nerve impulses?
Inner Ear
What is the scientific explanation for the differences between noise and music?
Music has a definite pattern and noise does not.
What is the wavelength of a sound wave?
The distance from one compression to another or from one rarefaction to another.
At what decibel does sound began to damage our eardrums?
85 decibels
What is another term(s) for the "timbre" or character of sound?
Which sounds, do people with age related hearing loss, have difficulty distinguishing?
a) "s" and "th" sounds
b) "v" and "b" sounds
c) "a" and "o" sounds
d) "a" and "e" sounds
The energy carried by a sound wave or the density of the particles in the compression and rarefaction of a wave, determine a sound wave's __________________.
Amplitude
For each 1 degree C increase in air temperature, the speed of sound increases by about 0.6 m/s.
Use the chart on page 337 in answer the following question.
What is the speed of sound in air at 21 degrees C?
343.6 m/s
What technology makes use of echoes underwater to measure distances?
Sonar
Because the sound produced by a vibrating string is not loud, most string instruments have a ____________ or hallow air-filled chamber.
Resonator
Which parts of the ear act as levers to amplify the motion of sound vibrations?
Hammer, Anvil and Stirrup
Although ultrasonic waves can not be heard by humans, they are beneficial to human's health.
Describe one way humans use ultrasonic waves in the medical field and why are they less harmful then X-Rays?
Ultrasonic waves are used to form images of the internal body called sonogram. Sonograms are used to monitor a fetus's development during pregnancy. They are less harmful then X-Ray's because they don't pose a radiation risk.