, AOL has been planning the switch to Dolby AAC (Advanced Audio Coding) for months, in the latest sign that the digital audio format is gaining momentum against competing technologies such as MP3.
AOL's decision comes at the expense of its longtime audio technology partner RealNetworks. Although AOL will continue supporting RealNetworks technology in other areas in its service, the longstanding relationship between the two companies has withered.
Much of the rift stems from AOL's internal efforts to build its own. AOL has touted the technology for allowing faster song loads and for its efficiency in delivering numerous simultaneous streams.
As part of the Dolby move, AOL will deploy Ultravox as the streaming backbone for Radio@AOL, which it claims will boost radio station load times. Other features will allow access to playlists from remote computers and station sharing through AOL Instant Messenger.
With Wednesday's announcement, AOL will become the latest online music service to embrace AAC, a technology developed by Dolby, AT&T, the Fraunhofer Institute and Sony Electronics., although Apple has created its own security wrapper.
Online subscription service MusicNet, which is owned by RealNetworks, AOL Time Warner, Bertelsmann and EMI Recorded Music, will also support AAC as one of many audio technologies, MusicNet CEO Alan McGlade said in a previous interview.
The Moving Pictures Experts Group (MPEG) has endorsed AAC as a specification in the latest version of its digital media standards, MPEG-4, and it could emerge as a challenger to MP3 and Microsoft's Windows Media audio format.
In a separate announcement, Loudeye said it will encode 1 million music files into Dolby AAC for AOL's radio services.