CALGARY, Aug. 13 /CNW/ - Advantage Energy Income Fund (TSX: AVN.UN,
NYSE: AAV) ("Advantage") and Sound Energy Trust (TSX: SND.UN) ("Sound") are
pleased to announce that the information circular and proxy statement (the
"Information Circular") with respect to the previously announced transaction
between Advantage and Sound (the "Arrangement") has been mailed to Sound's
Unitholders. The Information Circular contains a detailed description of the
Arrangement and is available on SEDAR (www.sedar.com) as well as on each of
Advantage's and Sound's Web sites (www.advantageincome.com and
www.soundenergytrust.com).
    The Special Meeting of Sound Unitholders to vote on the transaction will
be held on September 5, 2007 at 9:00 a.m. in the Grand Lecture Theatre of the
Metropolitan Centre, 333 - 4th Avenue SW, Calgary, Alberta.
    The Arrangement will provide for the integration of Sound into a larger
combined entity that will continue to operate under the Advantage name and
will be led by Advantage's existing management team. Sound Unitholders will
receive, at their election, either a) 0.30 of an Advantage unit for each Sound
unit; or b) $0.66 in cash and of an 0.2557 Advantage unit for each Sound unit.
The business combination is subject to, among other things, receipt of
approval of a minimum of 66 2/3 percent of Sound's Unitholders and the receipt
of approval of the Court of Queen's Bench of Alberta as well as the receipt of
all other required regulatory approvals. The Arrangement is expected to be
completed on or about September 5, 2007.
    All Sound Unitholders are encouraged to vote in person or by proxy at the
Special Meeting. For assistance in the voting process, Unitholders are invited
to call Computershare Investor Services at 1.800.564.6253 or any of the
contact numbers set out below.

    %SEDAR: 00020262E