If you click on
Source > About does Haali Media Splitter show both a video and audio graphic?
Further: AAC sound may be handled by
either ffdshow filter
or by
CoreAAC (click here).
In ffdshow maybe verify that "AAC / libfaad2" is also listed under "Codecs" of "ffdshow audio" (and that it isn't disabled there).
(You can access though Filters > Advanced etc.)
Alternatively (also if ffdshow Audio Decoder doesn't show under filters) try installing CoreAAC Audio Decoder.
P.S.: I happen to have CoreAAC installed and BS.Player uses it.