I think a lot of folks can get a bit confused when we talk bitrates as far as HD Radio is concerned. I have even encountered instances where someone mistook it as an equivalent to mp3 file bitrate. The two are not even close, as HD Radio uses a derivative of mpeg-4 high efficiency AAC V2 to compress audio data. The difference is more similar to the mpeg-4 technology that Satellite TV uses now to enable a "few hundred" more High Definition TV channels on the same ole pipe. Its still a lossy compression algorithm, but its selective lossy in that discarded data is primarily in the inaudible spectrum (way over inaudible for my old ears), and it incorporates technology like spectral band replication and parametric stereo.
Here is an interesting quote:
"Scientific testing by the European Broadcasting Union has indicated that HE-AAC at 48 kb/s was ranked as "Excellent" quality using the MUSHRA scale. MP3 in the same testing received a score less than half that of HE-AAC and was ranked "Poor" using the MUSHRA scale. Data from this testing also indicated that some individuals confused 48 kb/s HE-AAC encoded material with an uncompressed original." (that quote refers to HE-AAC v1, version 2 is a even better)
Near CD quality is a pretty conservative descriptor for HD Radio, since according to the mpeg-4 HE AAC V1 specification (ISO/IEC 14496-3, Amd.2:2004) actual CD quality is obtained at approx. 100 kbps. I am sure that the 96 kbps value employed by HD Radio factors in the V1 vs V2 differences. Considering that typical CD audio runs at over 1000 kbps uncompressed, I would say that its one hell of an impressive compression algorithm.
If we can dump analog radio entirely and switch to digital only, there appears to be quite a treat in store for us. I would certainly enjoy the CD quality digital surround sound emitted from my little HD Radio receiver if that ever transpires.