I don't either, and IBOC is the US standard. It is a poor system that only creates interference to weaker stations on the MW frequencies here. On FM, there isn't really the same issue because of the mode, but they had to lower the power output to 1/100th for both MW/FM of the analog signal due to adjacent channel interference on MW alone. That cuts the effective range of "HD Radio" (IBOC) down to just a few miles at best.
It's a joke, and a very poor one at that. On the plus side, DRM is the only
legal HF digital standard here in the US, but since we can't have domestic SW broadcasting it is not of much use.