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Chapter 26- Sound
Question | Answer |
---|---|
What is a beat? | periodic variation in the loudness of sound |
Resonance is... | 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... | rarefaction |
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. | Sound |
Vibrations send rhythmic_____impulses to the ____ which result in the sound of the voice. | electrical, brain |
All sounds originate in the _____ of material _______. | vibrations, objects |
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... | longitudinal waves |
The frequency of the vibrating object equals the frequency of the _____ ________. | waves produced |
Frequency is described as what? | Pitch |
What two things travel outward from the vibrating source? | Compressions and rarefactions |
Pulses are caused by what? | vibrations |
Energy travels, NOT ____. | medium |
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. | molecules |
The speed of sound in gasepends on: | the temperature, mass of the particles |
Speed of sound in material: | elasticity |
Light is faster than... | sound |
Water vapor and high temperatures increase/decrease speed of sound in air? | increase |
Intensity is ______, and loudness is sensed in the _____. | objective, brain |
Intensity (dB) is based on: | amplitude |
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. | produce, continue |
Sounding boards are NOT forced into vibration. T or F? | 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? | True |
What is the equation for frequency? | number of beats/second |