Processing Audio Files

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.

How Audio Files Are Processed

Audio files are processed as follows:

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

Parameters

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

Supported File Types

File Type	Extension	Content Type	Added In
wave	`.wav`	`audio/wav`	3.0.0
x-wave	`.wav`	`audio/x-wav`	3.5.0
mp3	`.mp3`	`audio/mpeg`, `audio/mp3`	3.0.0
mp4	`.mp4`	`audio/mp4`	3.0.0
m4a	`.m4a`	`audio/m4a`	3.5.0
m4a-latm	`.m4a-latm`	`audio/m4a-latm`	3.5.0
webm	`.webm`	`audio/webm`	3.5.0

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.

Support Matrix

	CPU Container	GPU Container	Community API	Professional API
Supported	Yes	Yes	Up to 10 MiB	No

Sample Request

Connect with one of our privacy experts to run this code.

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

echo '{
          "file": {"data": "'$(base64 -w 0 sample.wav)'", 
          "content_type": "audio/wav"}, 
          "entity_detection": {"return_entity": "True"}
      }' \
| curl --request POST --url 'https://api.getlimina.ai/community/v4/process/files/base64' \
       -H 'Content-Type: application/json' \
       -H 'x-api-key: <YOUR KEY HERE>' \
       -d @- \
       | jq -r .processed_file \
       | base64 -d > 'sample.redacted.wav'

import requests
import base64

file_url = "https://paidocumentation.blob.core.windows.net/$web/sample.wav"
filename_out = "/path/to/output/sample.redacted.wav"
file_content = requests.get(file_url).content
file_content_base64 = base64.b64encode(file_content).decode()

headers = {"Content-Type": "application/json", "x-api-key": "<INSERT API KEY>"}

url = "https://api.getlimina.ai/community/v4/process/files/base64"

payload = {
  "file" : {
    "data": file_content_base64,
    "content_type": "audio/wav"
  },
  "entity_detection": {
    "return_entity": True
  },
  "audio_options":{
    "bleep_start_padding": 0,
    "bleep_end_padding": 0
  }
}

response = requests.post(url, json=payload, headers=headers)
with open(filename_out, "wb") as f:
    f.write(base64.b64decode(response.json()["processed_file"]))

from privateai_client import PAIClient
from privateai_client.objects import request_objects
import base64

filename_in = "sample.wav"
filename_out = "sample.redacted.wav"

file_type= "audio/wav"
client = PAIClient(url="https://api.getlimina.ai/community/v4/", api_key="<YOUR API KEY>")

with open(filename_in, "rb") as b64_file:
    file_data = base64.b64encode(b64_file.read())
    file_data = file_data.decode("ascii")

file_obj = request_objects.file_obj(data=file_data, content_type=file_type)
request_obj = request_objects.file_base64_obj(file=file_obj)
resp = client.process_files_base64(request_object=request_obj)

with open(filename_out, 'wb') as redacted_file:
    processed_file = resp.processed_file.encode("ascii")
    processed_file = base64.b64decode(processed_file, validate=True)
    redacted_file.write(processed_file)

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}
}

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Processing Audio Files

How Audio Files Are Processed

Parameters

Supported File Types

VOX Files

Support Matrix

Sample Request

Sample Response

​How Audio Files Are Processed

​Parameters

​Supported File Types

​VOX Files

​Support Matrix

​Sample Request

​Sample Response

How Audio Files Are Processed

Parameters

Supported File Types

VOX Files

Support Matrix

Sample Request

Sample Response