Term
| What are the 3 basic qualities of sound? |
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Definition
1. Velocity
2. Frequency
3. Power |
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Term
| What is Velocity of sound relate to? |
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Definition
| this depends on the medium in which the sound is traveling and the teperature of the medium. |
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Term
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Definition
The number of cycles completed per second measured in Hertz (Hz)
1Hz = 1 cycle/sec |
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Term
| What does the Power of sound refer to? |
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Definition
the quality of acoustic energy as measured in watts.
it is the power that people precive as loudness. |
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Term
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Definition
The relationship of actual sound intensity to the way humans experience sound
0dB is the threshold of human hearing and 130dB is the threshold of pain. |
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Term
| What is Transmission loss in regards to sound? |
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Definition
| only takes into account the loss through the partition. |
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Term
| What is noise reduction in regards to sound? |
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Definition
| dependent not only on the trasmission loss but also on the area of the partition seperating the two spaces and the absorption of the surfaces in the room. |
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Term
What does STC stand for?
How is it used? |
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Definition
Sound transmission class
to rate the transmission loss of construction. the higher the number the better the barrier. |
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Term
| How is sound absorption used? |
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Definition
| To control unwanted sound reflections (noise), improve speech privacy, and decrease or increase reverberation. |
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Term
| What is the absorption of a material defined by? |
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Definition
| the coefficient of absorption,a, which is the ratio of the sound intensity absorbed by the material to the total intensity reaching the material. |
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Term
What does NRC stand for?
What is NRC? |
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Definition
Noise reduction coefficient
the average of a material's absorption coefficients at the four frequencies of 250, 500, 1000, and 2000 Hz, rounded tothe nearest multiple of 0.05. |
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Term
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Definition
| the prolongation of sound as it repeatedly bounces of hard surfaces. |
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Term
| What are the 3 primary ways sound can be controled in a room? |
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Definition
1. reducing the level of loudness of the sound source
2. modifying the absorption in the space
3. introducing nonintrusive background sound to mask the unwanted sound. |
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Term
| What are the 5 important factors in designing for speech privacy in an open area? |
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Definition
1. Ceiling must be highly absorptive.
2. Must include space dividers with absorptive qualities
3. other surfaces, floor, furn,windows, light fixtures must be arranged to minimize sound reflection.
4. If possible activities should be distanced to take advantage of the normal attinuation of sound with distance.
5. Area should have a properly designed background masking system. |
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Term
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Definition
the noise that is made when something is hit againt somthing else. most commonly on the floor or ceiling.
ex. dropping things on the floor. |
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Term
| How is impact noise quanified? |
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Definition
| the the impact insulation class (IIC) number. a single number rating of a floor/ceiling's impact sound performance. the higher the IIC rating the better the floor performs in reducing impact sounds. |
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Term
What does SRA stand for?
What is SRA? |
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Definition
Speech range absorption
A single number rating with frequency ranges of 500, 1000, 2000 and 4000 Hz.
this range is more closely represents the requencies of speech and may be a better rating to use in evaluation the selection of ceiling tile. |
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Term
What does CAC stand for?
What is CAC? |
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Definition
Ceiling Attenuation Class
a single number measure of the transmission loss through ceiling tiles between two closed rooms where ther is no wall or other barrier above the suspended ceiling.
measured in dB and is similar to STC. |
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Term
| What are the 2 methods used to measure speech privacy in open office? |
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Definition
1. Articulation Class (AC)
2. Articulaion Index (AI) |
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Term
What does AC stand for?
What is AC? |
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Definition
Articulation Class
a single number summation of how effective a ceiling is in absorbing sound reaching it from over low partitions. |
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Term
What does AI stand for?
What is AI? |
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Definition
Articulation index
measures the performance of all the elements of a particular configuration working together. it predicts the intelligibility of speech for a group of talkers and listeners. |
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