---
license: mit
tags:
  - audio
  - acoustic-echo-cancellation
  - coreml
  - dtln-aec
---

# DTLN-aec 256 (CoreML)

Stateful CoreML conversion of the **256-unit DTLN-aec** acoustic echo canceller,
for on-device real-time echo cancellation in [Narrato](https://github.com/) on
Apple Silicon (macOS 14.4+).

- **Source model:** [breizhn/DTLN-aec](https://github.com/breizhn/DTLN-aec)
  (`dtln_aec_256_{1,2}.tflite`), MIT licensed. Original work © Nils L. Westhausen.
- **Conversion:** `tflite → onnx → torch → CoreML` (see Narrato's
  `scripts/convert_dtln_aec_coreml.py`). Validated faithful to the original TFLite
  (RMS ~4e-4 through the full run_aec framing).

## Contents
- `dtln_aec_256_1.mlpackage` — stage 1 (magnitude domain).
- `dtln_aec_256_2.mlpackage` — stage 2 (time domain).
- `contract.json` — I/O + framing contract (block 512, hop 128, 257 bins, state [1,2,256,2]).

16 kHz mono. Two stages with an explicit LSTM state tensor carried frame-to-frame.