Issue link: https://www.e-digitaleditions.com/i/1255991
July/August/September 2020 I 59 EXAM ROOM EXAM ROOM EXAM ROOM EXAM ROOM RESTROOM RESTROOM EXAM ROOM WAITING ROOM OFFICE 20 FT SPACING 10 FT HIGH DROP CEILINGS RECEPTION WORK ROOM OFFICE FIGURE 2: Illustration of optimal speaker placement. Once these items have been assessed, the designer can begin to figure out a speaker placement strategy. The ceiling height, type of speaker and the dispersion angle is used to determine where speakers should be placed. As an example, if the speaker is thought of as a compass with the speaker in the center, typically 10 feet (approxi- mately 3.0 meters) from the center of the speaker can be covered when the ceiling height is 10 feet. With this information in mind, speakers can be spaced about 20 feet (approximately 6.1 meters) apart. Figure 2 shows a typical layout with 10-foot ceilings and speakers that are properly spaced apart in the hallways, exam rooms, waiting areas, office and restrooms. This design allows for proper placement and promotes intelligibility. It is worth mentioning the difference between audibil- ity and intelligibility. When someone can hear something, it is audible. When someone can hear something and understand what is being said, it is considered intelligible. While some designers may consider putting one speaker in a hallway and turning the volume all the way up, this procedure does not promote intelligibility. In most cases the dB level will be too high and distracting to the overall work environment. It is better to have more speakers at a reasonable dB to promote intelligibility throughout the facility. A desirable typical acoustic signal to noise (S/N) ratio is 10 dB. That means that regardless of the actual sound pressure level (SPL) the speech should be at least 10 dB