Since security systems were invented, audible warning devices have been used to "sound the alarm" when the security system is activated. In earlier years, bells and vibrating horns were the type of audible device most frequently used. In more recent times, sirens and other types of electronic sounding devices are commonly used in place of the bell or vibrating horn.

In a modern building, there may be literally dozens of different types of audible warning devices in use. Fire alarm systems, emergency exit alarms, elevators, electronic article surveillance systems, access control systems, and intrusion alarm systems can each have their own audible warning device. In an industrial setting, there may also be audible warning devices on production equipment, assembly lines, and on forklifts.

With so many different types of audible warning devices in use, it is sometimes confusing to building occupants when an alarm sounds. Is it the fire alarm? An emergency exit alarm? Or has a piece of production equipment jammed?

A "voice messaging system" can be used to supplement or replace many types of traditional audible warning devices. As its name implies, a voice messaging system plays a human voice when it has been activated. For example, if the fire alarm system has been activated, a voice messaging system could be be used to play a warning message that says "The fire alarm system has been activated, please evacuate the building immediately." The voice messaging system provides a clear and easily understood message to building occupants, and provides much more information than a simple bell or siren does.

Early voice messaging systems used an audio tape to record and play the message. These systems were expensive and not entirely reliable due to the potential for the tape to jam. Due to recent developments in electronic technology, there are a number of different types of digital voice messaging systems now available. These systems use an electronic memory chip to store the voice message and are very reliable.

There are two types of digital voice messaging systems available. The first type is what I call a "central voice messaging system". The central voice messaging system works in conjunction with a building public address (PA) system. Central voice messaging systems are used to broadcast a message throughout the entire building. These systems are ideal for situations where it is necessary to warn all occupants of the building, such as when the building fire alarm system has been activated. Central voice messaging systems are available in versions that have 4, 8, or 16 or more separate message "channels". Each channel has a unique voice message which can be activated separately. For example, if a building had four separate wings, a separate message could be played when the fire alarm was activated in a specific wing: .." or "the fire alarm system in the East Wing has been activated", or "the fire alarm system in the West Wing has been activated...", etc.

 

The second type of voice messaging system is what I call a "stand-alone voice messaging system". The stand-alone voice messaging system is a small self-contained unit that is designed to be used with one or two speakers. The stand-alone voice messaging system is ideal when it is necessary to broadcast a voice message only at a specific location. For example, a stand-alone voice messaging system could be used at a card reader controlled door in place of the traditional audible sounder. If the door was propped open, the system would play a voice message such as: "Warning - this door has been held open too long - please close the door behind you." Stand-alone voice messaging system are available with one or two voice message channels. These systems can cost as little as $250 installed, making them inexpensive enough to use in a wide variety of situations.

There are endless possibilities for using voice messaging systems in security-related applications. I'm sure that you can think of several uses for these systems in your own facility. Here are a few applications that we have encountered:

• Large distribution warehouse: Central voice messaging system used to annunciate emergency exit alarms on exterior warehouse doors. Allows emergency exit alarm to be heard throughout warehouse; allows supervisors to quickly respond to specific door where alarm originated.

• Large office building: Central voice messaging system tied to intrusion alarm system, plays warning message when intrusion alarm system has been armed. Prevents false alarms caused by employees who may still be in building when the intrusion alarm system is turned on.

• Corporate headquarters building: Central voice messaging system connected to panic button installed at main receptionist's desk. Activating panic button plays discrete message over building paging system to notify emergency response team that receptionist requires assistance.

• Hospital: Stand-alone voice messaging system connected to motion detector located at head of stairway leading to emergency exit door. Employees approaching the stairway are reminded that the door that they are headed to is for emergency use only and should not be used as an exit. Result: reduced false alarms.

• Heavy industrial facility: Stand-alone voice messaging system connected to motion detector located at entrance to chemical handling area. Employees approaching this area are reminded that they must carry respirator and other safety equipment when entering this area.

• Distribution center: Stand-alone voice messaging system connected to manual pushbuttons located at truck entrance to facility. Truck drivers can press button to receive specific driving directions to the destination to which they are headed.