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Documentation Index

Fetch the complete documentation index at: https://docs.getpatter.com/llms.txt

Use this file to discover all available pages before exploring further.

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DeepFilterNet Filter

DeepFilterNetFilter is a Patter AudioFilter backed by the DeepFilterNet3 deep-learning noise suppressor. Like Krisp, it runs as a pre-STT filter in pipeline mode: caller PCM enters the filter, cleaned PCM exits and is forwarded to the STT provider. DeepFilterNet is MIT-licensed and free. Use it as the default OSS noise-suppression option, or where Krisp’s commercial licence isn’t a fit.

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Install

DeepFilterNet works natively at 48 kHz; the filter resamples around inference automatically. Heavy deps (torch ~2 GB, model ~60 MB) are opt-in: 
pip install "getpatter[deepfilternet]"   # installs deep-filter + torch + numpy
TypeScript caveat. DeepFilterNet does not ship an official ONNX export for Node.js at time of writing. The TS filter targets onnxruntime-node and loads any user-supplied deepfilternet.onnx you point it at. If you don’t pass a modelPath, the filter logs a one-time warning and passes audio through unchanged — Patter never fakes enhancement. Once a stable community ONNX export with a streaming-friendly graph is published, point modelPath at it.

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Constructor

from getpatter.providers.deepfilternet_filter import DeepFilterNetFilter

filt = DeepFilterNetFilter(
    model_base_dir=None,        # None = use the bundled DeepFilterNet3 model
    atten_lim_db=None,          # optional attenuation cap in dB
)

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Usage in a pipeline agent

Plug it into phone.agent(audio_filter=...) / audioFilter:: 
import asyncio
from getpatter import Patter, Twilio, DeepgramSTT, AnthropicLLM, ElevenLabsTTS
from getpatter.providers.deepfilternet_filter import DeepFilterNetFilter

phone = Patter(carrier=Twilio(), phone_number="+15550001234")

filt = DeepFilterNetFilter()

agent = phone.agent(
    stt=DeepgramSTT(),
    llm=AnthropicLLM(),
    tts=ElevenLabsTTS(voice_id="rachel"),
    audio_filter=filt,                        # pre-STT noise suppression
    system_prompt="You are a helpful assistant.",
)

asyncio.run(phone.serve(agent))
See the audio_filter parameter on Agents (pipeline mode only).

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Resampling

DeepFilterNet operates at 48 kHz. Patter’s pipeline-mode audio bus runs at 16 kHz. The filter resamples up before inference and back down after, so callers see a filter that preserves the input sample rate.
  • Python: linear-interpolation resampler. Per-chunk; the boundary artefact is inaudible in practice.
  • TypeScript: StatefulResampler from audio/transcoding so chunk-boundary samples are not silently discarded. Resamplers are flushed on close().

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When to use DeepFilterNet vs alternatives

Use DeepFilterNet when…Use Krisp when…Skip filtering when…
You want OSS noise suppression with no licence step.You need best-in-class commercial-grade suppression and you have a Krisp licence.The line is clean (typical broadband VoIP / mobile in quiet conditions).

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Notes

  • On any internal error the filter logs and returns the original PCM unchanged — the call audio path is never broken.
  • Install footprint matters: the Python extra adds torch (~2 GB). For a smaller deploy where Python can’t ship torch, use Krisp (proprietary) or the (truly tiny) audio_filter=None baseline.
  • The TS filter is a faithful pass-through when no ONNX model is supplied — by design, so tests and audio-quality metrics stay truthful.

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What’s Next

Agents

The audio_filter parameter on phone.agent(...).

Krisp Filter

Proprietary commercial noise suppression.

Silero VAD

Voice activity detection downstream of the filter.

Pipeline mode

STT + LLM + TTS composition.