AVIXA CTS-D: PAG-NAG Exam Questions
With Correct Answers
PAG - answer✔✔Potential Acoustic Gain
is the potential gain that can be delivered by the sound system without ringing and before
feedback occurs. It is based upon the number of open microphones, and the distances between
source(s) (like a presenter) and microphone(s), microphones to loudspeakers, and listeners to
loudspeakers.
NAG - answer✔✔Needed Acoustic Gain
is to determine how much gain is needed to deliver the same level of sound to all the listeners in
the space
Is the gain the sound system requires to achieve an equivalent acoustic level at the farthest
listener equal to what the nearest listener would hear without sound reinforcement
EAD, Equivalent Acoustic Distance - answer✔✔Is the farthest distance one can go from the
source without the need for sound amplification or reinforcement to maintain good speech
intelligibility. It is a design parameter dependent on the level of the presenter and the noise level
in the room
Excessive background noise level will cause this to decrease.
Rule of Thumb for EAD for Voice - answer✔✔4 ft (1.2 meters) is often a safe bet for voice. This
assumes a 25 dB acoustic signal-to-noise ratio
Gain - answer✔✔Refers to the electronic amplification of a signal.
NAG Formula - answer✔✔20 log (D0 / EAD)