CTS Practice Questions

Listener 2

In sound propagation, every doubling of distance from a sound source generally results in a decrease of approximately 6 dB in sound level due to the inverse square law. Conversely, when moving closer to the sound source, the sound level increases by approximately 6 dB each time the distance is halved.

Given Listener 4 is at 20 feet from the speaker:

Listener 3 is at 15 feet, which is closer but not a direct halving of Listener 4's distance, so the change is less than 6 d

B.  

Listener 2 is at 10 feet, which is half the distance of Listener 4 (20 feet). This halving of distance results in a sound level increase of approximately 6 d

B.  

Listener 1 is at 5 feet, which is closer than Listener 2 and results in a higher increase in dB compared to Listener 4.

CTS Technology Specialist Reference

Understanding sound level changes over distance is essential in AV system design to ensure balanced audio coverage. The CTS materials cover the inverse square law extensively, explaining how sound pressure levels change as the distance from the sound source varies. Listener 2, at half the distance from Listener 4, receives sound at +6 dB compared to Listener 4, aligning with this principle.

Yellow-colored zones (any light fixture within the yellow zones directly above the seating area).

In video conferencing, balanced and well-placed lighting is crucial for achieving good facial visibility and reducing harsh shadows. Overhead lights can cast shadows on participants' faces, particularly under the eyes and nose, which can detract from a professional appearance on camera. By dimming lights directly above (in this case, the yellow zones), you reduce the intensity of the light falling straight down onto faces, softening shadows and creating more even lighting.

Dimming lights in the green or blue zones would be less effective, as they are positioned at the perimeter of the room and provide indirect lighting that does not directly influence facial shadows over the conference table.

CTS References: AVIXA CTS Exam Guide, Chapter on Lighting Considerations for Video Conferencing; CTS Handbook, Section on Proper Illumination Techniques for AV Environments.