The threat of chemical warfare has made gas masks a necessity for combat. However, communicating through the masks has always created a garbled message at best. Battelle engineer Ken Kimes has eliminated that problem by developing a tiny communications system that is attached to the gas mask and allows users to communicate in normal speaking tones. The lightweight system has potential uses for the military, firefighters, or handlers of hazardous materials.

"We wanted a system that would allow a person to use their normal speaking voice and still be heard clearly," Kimes said. "With this system we have better than 90 percent intelligibility." The system works in this manner:

• A clear plastic mask, which is attached to a cloth hood, covers the face.
• Just to the left of the mouth, embedded in the plastic, is a microphone about the size of a kernel of corn.
• A cable runs from the microphone, through the plastic mask, to an amplification unit. The amplification unit, which is about the size of a package of cigarettes, fits in a vest worn over the uniform.
• The amplification unit transmits the user's voice in normal volume, but can be turned up or down if needed. Because the hood that covers the user's head is made of thin material, there is no problem hearing.

The main advantage to the system is probably the most obvious. "If you're in the middle of a gas attack or a fire and you need to communicate critical information, you can't lift your mask up to talk to someone," Kimes explained. This system also includes a circuit that detects and eliminates feedback. "These units also have an output that is compatible with various two-way radios. Without a communications assistance device, you can't talk clearly through a radio unless you lift up the mask. With our unit, a cable will connect to the radio, so the user has only to push the transmit button and speak."

This application could benefit soldiers in a chemical attack, firefighters in a smoke-filled building, or a motorcycle cop wearing a full-protective helmet. The system operates on a 9-volt battery that fits inside the amplification unit.

For more information, contact Ken Kimes, Battelle, 505 King Ave., Columbus, Ohio 43201-2693; telephone (614) 424-3780; telefax (614) 424-3918.

Battelle serves industry and government by developing, commercializing, and managing technology. With a wide range of scientific and technical capabilities, Battelle puts technology to work for clients in 30 countries.