What Does AAC Stand For?

What does AAC stand for in audio?

Advanced Audio Coding is a way to compress sound. It removes parts of the audio that most listeners cannot hear, so a song takes far less space than the original recording. That kind of compression is called lossy, because some data is thrown away for good.

AAC was developed as a successor to MP3 and is part of the MPEG family of international audio and video standards. At the same file size, it usually sounds a little better than MP3, especially at lower quality settings. That is why many streaming services, video files and phones use it by default.

Other meanings of AAC by field

AAC in speech therapy and special education

Augmentative and alternative communication covers any method that adds to or replaces spoken language. It can be low tech, like a picture board or a book of symbols, or high tech, like a tablet app that speaks words aloud when a child taps them. Sign language and gestures can count too.

People who use AAC include children with autism, people with cerebral palsy and adults who have lost speech after a stroke. You may see the term in a school IEP or in notes from a speech language pathologist. In those papers, AAC has nothing to do with music files.

AAC vs MP3 and other audio terms

• AAC vs MP3: both are lossy formats. AAC is newer and usually more efficient, while MP3 plays on almost any older device.
• AAC vs lossless formats: lossless files keep every bit of the recording, so they are much larger.
• AAC vs MIDI: MIDI stores musical instructions, like which note to play, not recorded sound.
• AAC vs .m4a: .m4a is a file container that most often holds AAC audio, so the two usually travel together.

How to say and write AAC

Say the letters: "ay ay see." Some people say "double A C." The letters stay uppercase and go without dots. A vowel sound opens the term, so the article is an: "an AAC file," "an AAC device."

Example sentences:

• "The recorder saves voice memos as AAC to save space."
• "Convert the WAV file to AAC before you upload it."
• "Her AAC device lets her order lunch by tapping pictures."
• "Two AAC teams meet in the bowl game."

How to tell which AAC is meant

Look at the words around it. File names, settings menus and bitrates point to the audio format. School plans, therapy notes and words like "device" or "symbols" point to communication tools. Team names and standings mean the athletic conference. Building plans and wall specs mean concrete. For more digital media letters, explore our tech acronyms section, and if you wonder why AAC gets filed under initialisms, acronym vs abbreviation untangles those category names.