The Fairfax, Va.-based International Association of Fire Chiefs (IAFC) needs input from members who have experienced problems with unintelligible transmissions while using digital two-way portable radios. IAFC has received reports that close proximity to the low-pressure alarm on firefighters' self-contained breathing apparatus and other devices may be interfering with the transmissions.

IAFC's communications committee has formed a group to address the problem, which is not limited to any particular manufacturer's radio. Any digital voice communication product using parametric voice encoders could be subject to the problem.

Instructions for testing radios for the problem and a survey to report problems are available at www.iafc.org/digitalProblem.