Digital Danger

[brey1234]

The National Telecommunications and Information Administration (NTIA) has posted its report on radio intelligibility tests, particularly in a noisy fireground environment. Specifically, the NTIA tested digital radio systems to see if how they encode voice transmissions makes them more difficult to understand when there is background noise, such as ringing bells, rescue saws, sirens and engine noise. The tests included nine different environments using standardized speech. The tests found there was significant degradation of audio quality with firefighters' personal alarms and when using an air mask. Download (pdf) the full 86-page report here (http://www.its.bldrdoc.gov/pub/ntia-...453/08-453.pdf). The International Association of Fire Chiefs (IAFC) has also posted information (http://www.iafc.org/displaycommon.cf...articlenbr=719) about the intelligibility problems, and has come up with some Best Practices (http://www.iafc.org/associations/468...tPractices.pdf) (pdf)

[AZScanner]

Like we needed a report to tell us this. Anyone who has ever heard P25 fireground comms knows what that sounds like.

Fireground: "MMMPH ARR MEMPH MUM!"
Command: "What?"

But hey it's digital so now we're all 9-11 ready and stuff.

-AZ

[slicerwizard]

Air mask comms are hard enough to decipher over analog channels already. Let's distort them some more! Jeebus.

[wayne_h]

Already exists. http://www.radioreference.com/forums...d.php?t=107232