AAC file

File extension	.aac
Category	Audio File
Description	AAC is similar to MP3. It essentially cuts out, or compresses, information that the human ear cannot pick up thereby making digital files smaller and more easily managed and therefore quicker to download. AAC is about half the size of MP3 but with better quality. It is at least one tenth the size of CD digital data. Apple are the biggest users of this format and if you have an iPod or iPhone then you will have come across this format as it is iTunes default audio format.
Actions	AAC Converter View other audio file formats
Technical Details	AAC is similar in concept to MP3 but goes further. It too compresses digital audio files but to a bigger degree. It is also part of the MPEG-4 standard, it is most widely used to create small digital audio files. The current variant is specified in ISO/IEC standard 14496-3. Like MP3, AAC is a lossy algorithm. The human hearing system cannot hear quiet sounds in the presence of loud sounds of a similar frequency; for example, a voice conversation cannot be heard while an aeroplane flies low overhead. This is known as auditory masking, this allows the discarding of data with minimal loss of quality.
Associated programs	KMPlayer RealPlayer VideoLAN VLC Media Player Windows Media Player iTunes
Developed by	A combination of Fraunhofer IIS, AT&T Bell Laboratories, Dolby and Sony Corporation
MIME type	audio/aac
Useful links	More detail about the AAC file format How to play AAC files AAC Converter

Using Zamzar it is possible to convert AAC files to a variety of other formats

This page contains information on the AAC file extension (Advanced Audio Coding), a popular audio file format