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Limina supports scanning audio for PII and creating de-identified or redacted copies. Limina’s supported entity types function across each file type, with localized variants of different PII (Personally Identifiable Information) entities, PHI (Protected Health Information) entities, and PCI (Payment Card Industry) entities being detected. Our Supported Languages and Supported Entity Types page provides a more detailed look.

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How Audio Files Are Processed

Audio files are processed as follows:
  1. A transcript is produced using an Automatic Speech Recognition (ASR) system
  2. The resulting ASR transcript is passed through the text-based PII detection engine
  3. If specified by the user, the audio file undergoes pitch distortion
  4. Using the ASR timestamps, any sections of the audio file corresponding with PII detections are replaced with a Sine wave or bleep tone
  5. The resulting de-identified or redacted audio file and transcript are passed back to the user

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Parameters

Please see the audio_options object in the API reference for a full list of the parameters for audio processing.

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Supported File Types

File TypeExtensionContent TypeAdded In
wave.wavaudio/wav3.0.0
x-wave.wavaudio/x-wav3.5.0
mp3.mp3audio/mpeg, audio/mp33.0.0
mp4.mp4audio/mp43.0.0
m4a.m4aaudio/m4a3.5.0
m4a-latm.m4a-latmaudio/m4a-latm3.5.0
webm.webmaudio/webm3.5.0

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VOX Files

Note that .vox files are not natively supported by Limina, but can be processed by converting the .vox file to a wav or mp3 using a conversion tool like SoX. Because .vox files are headerless, you will need to know the sample rate and encoding to specify. For example, to take a vox file with a sample rate 8000, mono channel, mu-law encoded:
SoX Command
sox -t raw -r 8000 -c 1 -e mu-law myfile.vox myfile.wav
to generate a wav file.

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Support Matrix

CPU ContainerGPU ContainerCommunity APIProfessional API
SupportedYesYesUp to 10 MiBNo

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Sample Request

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{
  "file": {
    "data": "<file_content_base64>",
    "content_type": "audio/wav"
  },
  "entity_detection": {
    "return_entity": true
  },
  "audio_options": {
    "bleep_start_padding": 0,
    "bleep_end_padding": 0
  }
}

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Sample Response

Response
{
  "processed_file": "Base64 Encoded File Content of the Redacted File",
  "processed_text": "string",
  "entities": "List[Entity]",
  "entities_present": true,
  "languages_detected": {"lang_1": 0.67, "lang_2": 0.74}
}