Handbook for Sound Engineers

1566 Chapter 43

43.1.5.3 Emergency Crisis Communications

Methods of communications change, methods of trans-
mission change, and methods of installation change.
Manufacturers continue to upgrade their equipment to
handle these changes.
At one time the basic accepted method of signal
transmission was via copper conductors only, now there
are multiple methods to accomplish this.
Voice communications is often overlooked in some
areas, but an alert that is only a bell or horn or chime
sounding only alerts people that there is a problem, it
does not tell them what the problem is, where it is, or
what response they should take to protect themselves.
By adding voice communications to panic alarms, fire
alarms, or crash alarms, the general public can be
advised of what the nature of the alarm is, where it is,
and what to do to avoid it.
Often huge geographical areas must be covered. To
do this with copper alone is almost impossible. The
Ring Master Intercommunications Crisis Alert System
has the ability to tie equipment together to operate as
one complete system, providing for line supervision
over multiple methods of transmission, simultaneously
solving any such problem.
Fig. 43-8 shows such a system that is in use today to
cover the many and varied needs of an airport site.
The system provides communications for all aspects
of airport communications requirements over one inte-
grated supervised system. The system includes:

• Air traffic control.


• Security.
  
  
  • Baggage handling.
  
  
  • Staff location.
  
  
  • Access to general over-head paging.
  
  
  • De-icing.
  
  
  • Flight operations and planning.
  
  
  • ADA elevator communications.
  
  
  • Door access and control.
  
  
  • Emergency call boxes for the parking facilities.
  
  
  
  

When distances between buildings and operational

sites are long, copper is not a viable solution. Fiber is

better utilized to tie geographically distant areas

together. In other areas the newest method of VOIP,

over radio links, can be utilized to provide communica-

tions, for instance, to the people mover train system.

With this type of system, any station in the system,

no matter where its geographical location on the airport

site, can be programmed remotely, to call or be called

by any other station in the system or to access any of the

multiple functions and features of the communications

system at any time.

When these connection capabilities are added to the

commercial security intercom system there are virtually

no restriction to fulfill the requirements for safe, secure

communications.

43.1.6 Commercial/Industrial Systems

Commercial/industrial intercom systems are used in

airports, car dealers, dormitories, factories, hospitals,

nursing homes, department stores, and schools. Most of

these systems are master/slave systems or subsystems.

The health care and hospital facilities systems must

be designed for emergency hands-free operation from

operating rooms, trauma rooms, delivery rooms, etc.

The systems must also be capable of sterilization after

each use. This can be accomplished with a Mylar

covered face plate that is easy to sterilize because of

lack of crevices, etc. The system can include a paging

system for doctor, nurse, or security call and for calling

patient’s in waiting rooms.

Operations of general commercial/industrial systems

are very much like the door access or residential system

but include many of the following special features:

Absence Registration. A unit can be programmed to

display the station is unattended.

All Call. All call allows a master station to connect to

every other station for an all-call message.

Call Back. Call back is initiated by the caller when the

receiving line is busy. The caller can put the system on

automatic call back which notifies him as soon as the

Figure 43-7. Simulated firing of E.A.R. in an active subway
station. Courtesy Ring Communications, Inc.

Normal background conver-

sation, E.A.R. fires at scream

Fire level

Noise level

Train approaches; E.A.R.

adjusts base line and firing

pattern, fires at scream

Fire level

Base line

Base line

Baseline level

adjusts sound

pattern up to

background

noise levels.

Train noise level