I found an article from about 3 years ago that mentions it.
http://www.tomsguide.com/us/high-def-audio-hdmi,review-1088-4.html
"DTS-HD High Resolution
The DTS alternative to DD+, DTS-HD High Resolution (often simply called DTS-HD HR) provides
an enhancement to plain DTS similar to what DD+ offers over Dolby Digital,
including higher bit rates and improved compression characteristics.
Again, as with Dolby Digital and DD+, DTS-HD HR is encoded in the
form of an extension to the core DTS data. Likewise, DTS-HD HR is optional for
Blu-ray players as well, so many players extract only the 1.5 Mbps DTS core and ignore the extension data.
As with DD+, an examination of high-def tracks available for commercial Blu-ray discs
appears to indicate that the studios have forgone both of these formats in
favor of the original core format, plus the uncompressed high-bandwidth
versions — namely Dolby TrueHD and DTS-HD Master Audio. Apparently,
the guiding notion seems to be to provide the highest possible fidelity with i
ts inner compressed 5.1 core, so that equipment that can handle uncompressed
audio can work with those bitstreams, and other equipment defaults to the compressed core 5.1 formats (Dolby Digital and DTS).
Here again, we can find no Blu-ray discs that incorporate DTS-HD HR encodings.
Though some foreign import HD DVD titles from Warner Brothers indicate
support for this format, reviews of such discs indicate that Blu-ray versions
that support Dolby TrueHD or DTS-HD Master Audio offer vastly superior
sound when compared to their HD DVD counterparts — see, for example,
this review of Ghost Rider (French Import). If there were to be a database
entry for such an unlikely beast, following our earlier entries, here’s what it might look like:
The Audio Codec is DTS-HD High Resolution.
The Audio Channels (sound scheme) can appear as 5.1 (most typical) or 7.1 (unusual).
Audio Fidelity data: the DTS-HD specification indicates it is 24 bits deep,
and can be recorded at 48 kHz (typical for HD DVD) or 96 kHz
(would probably be used for Blu-ray, but there aren’t any).
Audio Bit Rate values can go as high as 6.144 Mbps for encoded data,
but might be either 1.5, 4.5, or 6.144 Mbps, depending on the bandwidth
that the studio decides to allocate to this type of audio track.
Those HD DVDs that supported DTS-HD invariably used 1.5 Mbps bitrates.
See Table 1 for more information about sound schemes, SPDIF, and HDMI
handling for DTS-HD High Resolution. Interestingly, despite a total lack of
DTS-HD encodings on Blu-ray discs, numerous players (including models from Panasonic, Onkyo, and Samsung)
support DTS-HD, though I can find no mention of Sony’s support for this format,
except through a firmware upgrade for the PS3. According to various sources,
DTS-HD HR achieves compression ratios of around 3:1.
DTS-HD HR is another constant bitrate (CBR) encoding, which means it operates
at the same bitrate at all times, regardless of the compressed audio material it is
handling at any given moment. Most serious listeners who compare DTS and Dolby Digital
to DTS-HD HR and DD+ are quick to observe that despite their apparent
similarities (constant bitrate encoding, lossy compression algorithms),
both of the “advanced” versions deliver better sound quality than their standard DD and DTS counterparts.
DTS-HD builds a set of enhanced extensions around a DTS encoding core,
so even if extensions can’t be played back, the core DTS sound track remains available and accessible."
Further looks seem to show that only non U.S. releases have used the HR sound format.
Would be very odd for Disney to do this.
Colin do you have the disc and can verify this?