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Chapter 26- Sound
|What is a beat?
|periodic variation in the loudness of sound
|the phenomenon that occurs when the frequency of a vibration forced on an object matches the object's natural frequency
|What is forced vibration?
|occurs when an object is made to vibrate by another vibrating object that is nearby
|Natural frequency is...
|the frequency at which an object vibrates when it is disturbed- depends on the elasticity andn shape of the object
|A pulse of low-pressured air is...
|Describe a compression...
|a pulse of compressed air
|Ultrasonic refers to what?
|any frequency above 20,000 Hertz
|Infrasonic refers to what?
|any frequency below 20 Hertz
|What is pitch?
|a subjective impression about the frequency of sound
|____ is a form of energy that spreads throughout space.
|Vibrations send rhythmic_____impulses to the ____ which result in the sound of the voice.
|All sounds originate in the _____ of material _______.
|Although the original vibration is small, what helps it vibrate?
|The vibration causes something bigger than it to vibrate.
|Vibrations in air come in the form of...
|The frequency of the vibrating object equals the frequency of the _____ ________.
|Frequency is described as what?
|What two things travel outward from the vibrating source?
|Compressions and rarefactions
|Pulses are caused by what?
|Energy travels, NOT ____.
|Sounds travel in:
|solids, liquids, and gases
|Order of speed from Fast to Slow:
|solid, liquid, gas
|If there are no _____ to compress and expand, there is no sound.
|The speed of sound in gasepends on:
|the temperature, mass of the particles
|Speed of sound in material:
|Light is faster than...
|Water vapor and high temperatures increase/decrease speed of sound in air?
|Intensity is ______, and loudness is sensed in the _____.
|Intensity (dB) is based on:
|Sound levels: threshold of pain ____.Normal speech _____.Close whisper _____.
|120, 60, 20
|What is Corti?
|the receptor organ in the inner ear
|Loud is to ____ as low is to ______.
|tall, less peaks
|Soft is to ____ as high is to _____.
|short, more peaks
|When an object of elastic is disturbed it does what?
|It vibrates at its own set or frequencies.
|Minimum to ____, least to ______ the vibration.
|Sounding boards are NOT forced into vibration. T or F?
|When does an object resonate?
|When there is a force to pull it back to its starting position and energy to continue the vibration.
|Constructive interference is when a:
|compression and compression overlap
|Destructive interfernce is when a:
|compression and rarefaction overlap
|Beats are caused when 2 mismatched frequencies are sounded together. True or False?
|What is the equation for frequency?
|number of beats/second