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

Other AAC conversions

AAC to Text

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AAC to Subtitles

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Other file formats

FLAC to text
CAF to text
OGG to text
GSM to text
WEBA to text
MP3 to text
AU to text
XSPF to text
MPGA to text
AIFF to text
See all supported file formats
Reviews

Trusted by accessibility teams

4.98 rating from 211 reviews

Sonix is quick and easy to use! It's efficient and transcriptions were very close to perfect - only a little editing needed!!
EC
Emma C.
London, England
We love transcribing with Sonix. Your interface for subtitle editing is excellent.
MG
Manuel G.
Madrid, Spain
The highest accuracy I have ever achieved through similar services.
JB
John B.
Townsville, Australia
The interface and editor experience were great. I also like the way you handle speaker identification and naming. Pretty slick. Nice timestamp frequency / formatting too.
JD
JP D.
Ottawa, Ontario Canada
I am a video editor and I found you by trying a few services with free trials. Sonix was far, far superior as well as an easy process to trial enroll.
PW
Polly W.
Guadalajar, Mexico
The transcription service was awesome. I can’t thank Sonix enough.
GI
Glenda I.
San Diego, CA USA
I love your product. I saw the results, and was hooked. Your website is brilliant. SO very easy to navigate and utilize. Your product is game-changing for my busin...
SP
Shelly P.
Gloucester, MA USA
I have been a dialogue system researcher for half a decade now. I had build my own app for doing the transcriptions. Sonix was clearly better than what I had. I made the switch!
RM
Ramesh M.
Portland, OR USA
Read more testimonials
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