Furniture; Acoustics - Polycom RealPresence Group Series Reference Manual

Room Design and Layout
In keeping with these color recommendations, the acoustic panels (discussed elsewhere in this section)
should be ordered in light colors such as silver-gray, quartz or champagne for panels within the camera field
of view. For aesthetics, however, panels may be alternated in color along the wall.

Furniture

As we have noted, VC rooms should be slightly on the large side for the typical number of attendees. The
placement of furniture should present a natural rapport with the videoconference system, but shouldn't
preclude the local interaction of conference participants. Doorways used for access to the space usually
should be within the view of one of the camera presets to prevent the perception from the far-end that people
could come into their meeting unseen. Doorways should not, however, be in constant, direct view of the
camera system, as this may cause unwanted distractions and movement of people in the picture field.
Any tables within the conference environment should have a light top surface. Glossy tops should be
avoided, as should strong colors or any bold wood grain. If glossy or saturated color surfaces are
unavoidable, then proper lighting can help reduce (but not necessarily eliminate) their ill effects. The best
table surface color is a flat satin finish, in neutral gray. In cases where the worst possible surfaces are
present, the proper surface color effect can be achieved by using a table covering, put in place only when
the room is being used for videoconferencing. This will, however, create problems related to the use of
access ports in the tables or movement of end-user items across the surface.

Acoustics

Additional general elements related to the interior finish details for the space include acoustics. In terms of
ambient noise level, the acoustic design goal for any conference- enabled room is at least NC-30
(NoiseCriteria-30). This level of specification dictates a very quiet space (somewhere around 40-dBCSPL
ambient noise level). A room built to the description found elsewhere in this section will usually fall between
NC-30 and NC-35. The actual NC value is not critical; what is important is that the room be built with the
intent and care required to achieve the low noise rating. Typically in architectural design, a site evaluation
and analysis are required to certify the noise performance of a given space. The quieter the room, the easier
it is to hear others in the same room as well as be heard by others who are participating via conference
connection to a far-end location (or locations).
Almost every conference room of medium to large size (larger than 12'x15') requires some level of acoustic
treatment to provide good speech-rendering to other conference sites. The quality differences lie in the
areas of intelligibility and consistency of loudness as presented to the far-end. While the people at the
far-end may hear the sounds coming to them, it may be hard for them clearly to distinguish all of the vowels,
consonants, inflections and nuances of actual human speech communication. (We all know that it is not
simply what you say but how you say it—i.e., the inflections and intonations—that makes the difference in
perceived meaning in human communications.)
Good audio practice dictates that the treated surfaces be composed of at least two nonparallel walls. And,
as the VCS hardware is a potential source of distracting fan noises, the walls to be treated should include
the wall immediately behind the VCS hardware, whenever this hardware is within the conference room
proper. To help prevent meeting audio from leaking into adjoining hallways or offices, the walls along those
areas also should be treated.
Approximately 50 percent of the wall area needs be covered with acoustic panels. The type recommended
is 1" thick compressed, dense-core fiberglass, fabric-covered, or equivalent, with a SABIN (sound
absorption index) value of 0.9 average. This specification is sometimes referred to as NRC (noise reduction
coefficient). If reduction of sound passing through is required, then an additional barrier layer is laminated
to the dense-core material, usually 3/8" thick fiber compression board. The barrier layer is placed against
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