Skip to content

To make a smart speaker

>> Github

Here is a collection of resources to make a smart speaker. Hope one day we can make an open source one for daily use.

The simplified flowchart of a smart speaker is like:

+---+   +----------------+   +---+   +---+   +---+
|Mic|-->|Audio Processing|-->|KWS|-->|STT|-->|NLU|
+---+   +----------------+   +---+   +---+   +-+-+
+-------+   +---+   +----------------------+   |
+-------+   +---+   +----------------------+
  • Audio Processing includes Acoustic Echo Cancellation (AEC), Beamforming, Noise Suppression (NS), etc.
  • Keyword Spotting (KWS) detects a keyword (such as OK Google, Hey Siri) to start a conversation.
  • Speech To Text (STT)
  • Natural Language Understanding (NLU) converts raw text into structured data.
  • Knowledge/Skill/Action - Knowledge base and plugins (Alexa Skill, Google Action) to provide an answer.
  • Text To Speech

KWS + STT + NLU + Skill + TTS

Active open source projects

  • Mycroft - a hackable open source voice assistant
  • dingdang robot - a Chinese voice interaction robot based on Jasper and built with raspberry pi


It has the smartest brain, its extension called Google Action can be created on a few steps with and its Device Action is very suit for home smart devices.


  • Mycroft Precise - A lightweight, simple-to-use, RNN wake word listener
  • Snowboy - DNN based hotword and wake word detection toolkit
  • Honk - PyTorch reimplementation of Google's TensorFlow CNNs for keyword spotting
  • ML-KWS-For-MCU - Maybe the most promise for resource constrained devices such as ARM Cortex M7 microcontroller




  • Mimic - Mycroft's TTS engine, based on CMU's Flite (Festival Lite)
  • manytts - an open-source, multilingual text-to-speech synthesis system written in pure java
  • espeak-ng - an open source speech synthesizer that supports 99 languages and accents.
  • ekho - Chinese text-to-speech engine
  • WaveNet, Tacotron 2

Audio Processing

  • Acoustic Echo Cancellation

  • SpeexDSP, its python binding speexdsp-python

  • EC - Echo Cancelation Daemon based on SpeexDSP AEC for Raspberry Pi or other devices running Linux.

  • Direction Of Arrival (DOA) - Most used DOA algorithms is GCC-PHAT

  • tdoa

  • odas - ODAS stands for Open embeddeD Audition System. This is a library dedicated to perform sound source localization, tracking, separation and post-filtering. ODAS is coded entirely in C, for more portability, and is optimized to run easily on low-cost embedded hardware. ODAS is free and open source.

  • Beamforming

  • BeamformIt - filter&sum beamforming

  • CGMM Beamforming - a reference implementation
  • MVDR Beamforming
  • GSC Beamforming

  • Voice Activity Detection

  • WebRTC VAD, py-webrtcvad


  • Noise Suppresion

  • NS of WebRTC audio processing, python-webrtc-audio-processing

Audio I/O