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CFPS Exam - Question 3


The performance of fire alarm audible notification in a wide open space can be analyzed using a condition called free-field condition, where the sound pressure level (SPL) decreases roughly by a specific decibel value every time the distance from the source is doubled. Which of the following choices is the specific decibel value attributed to the free-field condition?

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Correct Answer: D

The free-field condition describes how sound propagates in an open space without significant reflections or obstructions. In such conditions, the sound pressure level (SPL) decreases by 6 decibels (dB) every time the distance from the sound source is doubled. This is a well-established acoustics principle known as the inverse square law.

Discussion

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asim990Option: D
Jun 29, 2023

the answer is D check the handbook 14-30

howmany
Apr 10, 2023

Correct answer is C : 6dB rule

Chris_S723Option: D
Jul 5, 2023

6dB Rule.

lengochoOption: D
Dec 22, 2023

ANS: D 6dB. FPH 14-30