Convert AAC to captions

Create accessible closed captions from your AAC audio. Convert streaming content to professional captions meeting accessibility standards.

ADA compliant
5-min turnaround
Accessible
Audio
Video
DOCX
SRT/VTT
PDF
53+ Languages
About This Format

Understanding AAC files

What is a AAC file?

High-quality compressed audio, Apple's preferred format

Advanced Audio Coding (AAC) is the default encoding used by Apple iTunes and the iTunes Music Store. It is a compressed audio file similar to an .MP3 file, but offers several performance improvements; examples include a higher coding efficiency for both stationary and transient signals, a simpler filterbank, and better handling of frequencies above 16 kHz; maintains quality nearly indistinguishable from the original audio source.

Common Uses

  • iTunes music
  • Apple podcasts
  • Streaming audio
  • Professional audio distribution

Audio Quality

Superior quality to MP3 at equivalent bitrates

Transcription Tips for AAC

  • AAC at 128kbps+ yields excellent transcription accuracy
  • Supports clear speech frequencies well

Where AAC Files Come From

  • Apple iTunes Store
  • Apple Music
  • iOS voice recordings
  • Podcast apps
10x
Faster than real-time
Get your AAC captions in minutes
99%
Accuracy rate
Industry-leading AI for AAC files
53+
Languages
Captions in any language
30+
Export formats
SRT, VTT, SCC, and more
How It Works

Create captions from AAC in 6 steps

Step 1

Create account

Sign up for Sonix's free trial. Includes 30 minutes free.

Step 2

Upload file

Upload your AAC file from your computer or cloud storage.

Step 3

Select language

Choose from 53+ languages spoken in your file.

Step 4

Auto-transcribe

Sonix AI transcribes your AAC with word-level timestamps.

Step 5

Edit captions

Fine-tune timing and formatting for accessibility.

Step 6

Export

Download closed captions in SRT, VTT, or SCC format.

Common Questions

Everything about AAC captions

What's the difference between captions and subtitles for AAC?

Captions include speaker identification and sound descriptions for deaf viewers. Subtitles focus on dialogue translation. For accessibility, choose captions.

Are AAC-to-caption conversions ADA compliant?

Sonix generates captions meeting ADA requirements when you include speaker labels and review for accuracy. AAC's quality helps achieve high accuracy.

Can I add sound descriptions to AAC captions?

Yes! After transcription, add descriptions like [music], [applause], or [door closes] in Sonix's editor for fully accessible captions.

How do I add speaker labels to AAC captions?

Sonix automatically detects speakers during transcription. Customize names before exporting captions.

What caption format works for broadcast AAC?

For broadcast television, export to SCC or STL formats which meet FCC requirements.

How accurate are AI captions from AAC?

Sonix achieves 99%+ accuracy on clear AAC audio. AAC's superior codec helps maintain accuracy even at lower bitrates.

Why Sonix

Accessible captions from AAC files

Accessibility First

Create captions that make your content accessible to deaf and hard-of-hearing viewers.

ADA Compliant

Meet accessibility requirements with properly formatted closed captions.

Sound Descriptions

Add non-speech elements like [music] and [applause] for full context.

SEO Benefits

Captions make video content searchable and improve discoverability.

Related

More ways to convert AAC files

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Other file formats

OPUS to text
AMR to text
FLAC to text
AIFF to text
MPA to text
MPGA to text
AIFC to text
AIF to text
OGG to text
MUS to text
See all supported file formats
Reviews

Trusted by accessibility teams

4.98 rating from 211 reviews

Having tried numerous transcription services, this was undoubtedly the best. There were features (such as the synching up of the audio to the words for review) that I hadn’t ever hoped to find.
RD
Raeven D.
Montreal, Canada
Sonix is faster and better than YouTube at making captions for my videos!
FN
Francisco N.
Concepcion, Chile
I was simply awed by speed and accuracy of your transcription service.
MK
Myung K.
Queens, NY, USA
You saved me! I got everything done in three days and I was sure it will take me a month.
WO
Wojciech O.
Gandsk, Poland
I love how easy and intuitive it is to use Sonix! I can now put my energy and focus on actual content, instead of going through the tedious and time consuming process of transcribi...
EL
Elina L.
San Francisco, CA USA
I need to produce very accurate transcripts and the initial transcripts Sonix produces are much better than competitors (I've used many others).
SC
Sandy C.
Fountain Valley, CA USA
I came across Sonix by accident... and boy was I glad I did. This tool is virtually word perfect and the SRT file it output worked perfectly...
JW
John W.
London, United Kingdom
I loovvvve that the audio is transcribed so quickly.
SB
Sandra B.
San Francisco, CA USA
Read more testimonials
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Create AAC captions now

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