Clear and concise radio transmissions are an essential component of every fireground operation. They are necessary in order to ensure the safety of all members operating at an incident. Garbled and unintelligible messages can prevent incident commanders from receiving important or even critical information that is needed to make the proper decisions while conducting the operation. Since switching to the 800 MHz digital radio system several years ago, the Washington, D.C. Fire Department (DCFD) has experienced an increase in problems with radio transmission intelligibility on the fireground.

Intelligibility problems, such as these have also occurred quite often while conducting training evolutions. We recently conducted department-wide rapid intervention drills as a part of our ongoing "back to basics," in-service training. Many of the radio transmissions made during these drills were difficult to hear and understand due to low voice volume, or were completely unintelligible due to background noise. It was later discovered that some of these unintelligible transmissions could be directly attributed to a combination of members positioning the remote speaker microphone too far from the self-contained breathing apparatus (SCBA) face piece voice port (see Photo 1) as well as the presence of excessive fireground background noise during the transmission.

This problem is not limited to our department by any means. In 2006, the International Association of Fire Chiefs (IAFC) began receiving reports of possible communications problems involving digital portable radios that were operating in close proximity to common fireground noises such as SCBA low air alarms, PASS devices, power saws and fans. Because of this, the IAFC has established a committee to look into this issue. The committee is composed of representatives from the fire service, law enforcement, government as well as the radio system manufacturers.

As a result of their research into this issue, the IAFC committee has come up with a set of best practices for operating portable radios in a high-noise environment: