Well, the situation is a bit confusing.
Firstly, DVD-Audio itself is completely free from region coding - you can buy any DVD-Audio disc anywhere and play it on any DVD-Audio player.
However, it`s also possible for a DVD-Audio disc to have DVD-Video content, and this part of the disc can have region codes just like a standard DVD-Video disc.
So a DVD-Audio release can in fact be "region 1" - but this restriction *only* applies to the DVD-Video portion of the disc, not the main DVD-Audio part. Hope that makes sense.
Mike