For its part, NPR indicated that while its member stations have an enormous investment in IBOC digital technology, evidence of significant interference potential already exists, and that forthcoming data is essential in establishing clear parameters for dealing with issue.
Perhaps one of the most striking points made by NPR involves the burden of proof in interference cases. While proponents of an across-the-board increase suggest that any resulting interference could be addressed by the Commission after the fact, such an approach would serve to shift the burden to the plaintiff station, imposing consulting engineering expenses that could prove onerous for small LPFM and NCE stations. NPR's comments suggest that the burden rightly ought to be borne by the station boosting their facility, as they currently are in the case of analog power increases.
NPR also notes a serious question as to whether analog listeners would perceive digital interference as such. Since adjacent channel digital interference tends to manifest as white noise in a receiver, it is suggested that the average listener is far more likely to conclude that the desired station's signal is simply too weak to listen to, resulting in tune-out.
Fundamentally, both sides agree that increases to IBOC digital carrier levels are needed to ensure a reasonable level of service, and that such a move needs to come quickly. NPR even went so far as to offer a simple algorithm for establishing elevated digital carrier levels on an interim case-by-case basis.
But the argument that a decision delay of another 60 days could irreparably tarnish HD Radio's future shouldn't outweigh the documented interference potential poised by a cookie-cutter approach. The Commission has a compelling obligation to act in the public interest, and that includes assuring a vast majority of citizens that depend on analog FM today will continue to so without impediment for the immediate future.
It's notoriously difficult to put toothpaste back in the tube once it's been squeezed out. Let's hope the FCC recognizes that it's better to wait 60 days and have the best available information before making a key decision that could impact FM broadcasters for years to come.