Speech intelligibility is critical in conference rooms. To guarentee privacy, they have reduced noise from air conditioning, mechanical systems and outside noise sources. The room should have a reverberation time from .5 to .75 seconds. The lower the reverberation time in the room, the better the speech intelligibility.
It is usually the responsibility of the architect or design engineer to pre design the mechanical systems using Noise Criteria Curves (ambient room noise level graphs) based on the intended room usage.
There are several methods that we typically employ to treat conference rooms: