Originally Posted by Mike Walker
If the bitrate is 32kbps, it ought to sound EXACTLY LIKE AM HD. Same codec, same bitrate. At a lower bitrate, it ought to sound worse.
Actually there is a new codec technology that HD Radio is implementing so that 12KB/s HD signal when broadcasting voice can sound as good as 36KB/s. It was originally being used in cell phones to help improve voice communication trunk lines.
I have heard this. It does sound OK. I have received it in HD AM and it does sound good.