Text-To-Speech

Text-To-Speech (TTS) is the process of synthesizing audio from text. Mycroft uses our own TTS engines by default, however we also support a range of third party services.

Mycroft has two open source TTS engines.

Mimic 1 is a fast, light-weight engine based on Carnegie Mellon University's FLITE software. Whilst the original Mimic may sound more robotic, it is able to be synthesized on your device.

Mimic 1

Mimic 2 is an implementation of Tacotron speech synthesis. It is a fork of Keith Ito's project with additional tooling and code enhancements. Mimic 2 provides a much more natural sounding voice, however requires significant processing power to do so and is therefore cloud-based.

Default Engine

The engine that will be used depends on the voice selected in your Device Settings at Home.mycroft.ai.

Currently:

  • British Male is Mimic 1

  • American Female is Mimic 1

  • American Male is Mimic 2

  • Google Voice uses the Google Translate TTS API.

As Mimic 1 voices can be synthesized on device, the British Male voice will be used anytime the device cannot reach your preferred TTS service. This allows Mycroft to continue to speak even if it is not connected to a network.

eSpeak

A multi-lingual software speech synthesizer for Linux and Windows.

eSpeak uses a "formant synthesis" method. This allows many languages to be provided in a small size. The speech is clear, and can be used at high speeds, but is not as natural or smooth as larger synthesizers which are based on human speech recordings.

Mycroft Configuration

First, ensure that the espeak package is installed on your system.

sudo apt-get install espeak

Then, using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "espeak",
  "espeak": {
    "lang": "english-us",
    "voice": "m1"
  }
}

Added in mycroft-core v21.2.2

You can further customize the amplitude, gap, capital, pitch and speed of espeak voices by adding them to your TTS configuration parameters.

Example Config:

{
  "max_allowed_core_version": 21.2,
  "lang": "de-de",
  "tts": {
    "module": "espeak",
    "espeak": {
      "lang": "german-mbrola-5",
      "voice": "german-mbrola-5",
      "speed": "135",
      "amplitude": "80",
      "pitch": "20"
    }
  }
}  

For more information on the values for these parameters see espeak --help

Mary TTS

The multilingual open-source MARY text-to-speech platform. MaryTTS is a client-server system written in pure Java, so it runs on many platforms.

Server Setup

The latest installation instructions can be found on the MaryTTS Github repository.

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

  "tts": {
    "marytts": {
      "url": "http://YOUR_SERVER:PORT_NUMBER"
    },
    "module": "marytts"
  }

FA TTS

Produced by Mivoq, it is based off Mary TTS.

Server Setup

The latest installation instructions can be found on the Mivoq FA TTS Github repository.

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

  "tts": {
    "fatts": {
      "url": "http://YOUR_SERVER:PORT_NUMBER"
    },
    "module": "fatts"
  }

Amazon Polly

Amazon Polly's text-to-speech service.

Account Setup

Create an AWS account and add the Polly service.

You will need to take note of your private "Access Key ID" and "Secret Access Key".

Mycroft Configuration

First, check the list of available voices and languages. Note that Polly does not provide a separate language attribute like other TTS options. The language is determined by which voice is chosen.

Then, install the boto3 python module in the Mycroft virtual environment:

mycroft-pip install boto3

or

cd ~/mycroft-core
source .venv/bin/activate
pip3 install boto3
deactivate

Finally, using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "polly",
  "polly": {
    "voice": "Matthew",
    "region": "us-east-1",
    "engine": "standard",
    "access_key_id": "YOUR_ACCESS_KEY_ID",
    "secret_access_key": "YOUR_SECRET_ACCESS_KEY"
  }
}

If the voice, region, and engine attributes are ommitted the defaults of Matthew, us-east-1 and standard will be used. This is an English (US) voice.

Google TTS

Google Translate's text-to-speech API.

The Google TTS module uses the gTTS Python package which interfaces with the Google Translate text-to-speech API. This is not intended for commercial or production usage. The service may break at any time, and you are subject to their Terms of Service that can be found at: https://policies.google.com/terms

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config set tts.module "google"

IBM Watson

Account Setup

Create an account at IBM.com/cloud. Once you add the TTS service to your account, you will receive an API key and unique API url.

You can find a list of available voices at Languages and Voices. For example, "en-US_MichaelV3Voice".

IBM keeps a log of all requests in the lite plan unless you turn it off explicitly by setting "X-Watson-Learning-Opt-Out" to true. We have set Mycroft to Opt-Out by default, so if you want to share data with IBM then you must set this to false.

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "watson",
  "watson": {
    "voice":"PREFERRED_VOICE",
    "apikey": "YOUR_API_KEY",
    "url": "YOUR_API_URL",
    "X-Watson-Learning-Opt-Out": "true"
  }
}

Microsoft Azure Cognitive Service

Note: This is a Community provided TTS plugin and is not controlled by Mycroft AI. Updates for this plugin may not have been reviewed by the Mycroft team. We strongly recommend reviewing any code you intend to install from outside Mycroft's official channels.

Installation

mycroft-pip install mycroft-tts-plugin-azure

Account Setup

This TTS service requires a subscription to Microsoft Azure and the creation of a Speech resource (https://docs.microsoft.com/en-us/azure/cognitive-services/speech-service/overview#create-the-azure-resource) The free plan is more than able to handle domestic usage (5 million character per month, or 0.5 million with neural TTS voice)

Mycroft Configuration

You can choose your voice here in the column "voice name" (https://docs.microsoft.com/en-us/azure/cognitive-services/speech-service/language-support#text-to-speech) Neural voices are much better, but cost more.

"tts": {
  "module": "azure_tts",
  "azure_tts": {
    "api_key": "insert_your_key_here",
    "voice": "en-US-JennyNeural", # optional, default "en-US-Guy24kRUS"
    "region": "westus" # optional, if your region is westus
  }
}

Microsoft Bing

Account Setup

Create a Microsoft Azure account and get a server access token.

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "bing",
  "bing": {
    "api_key": "YOUR_API_KEY",
    "format": "riff-16khz-16bit-mono-pcm",
    "gender": "Male"
  }
}

Mozilla TTS

Server Setup

Instructions for setting up a Mozilla TTS server are available on the projects wiki.

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "mozilla",
  "mozilla": {
    "url": "http://my-mozilla-tts-server"
  }
}

By default the url is set to the localhost: http://0.0.0.0:5002 So if you are running the server on the same machine as your Mycroft instance, only the module attribute needs to be set. This can also be done with a single command:

mycroft-config set tts.module mozilla

Coqui TTS

Coqui TTS is an actively maintained fork of the Mozilla TTS project. A Coqui TTS server can be run locally without internet connection.

Pretrained TTS models are available based on open voice datasets (eg. LJSpeech, LibriTTS, Thorsten-DE, Mai, ...). The Coqui release page shows a complete list of available TTS models.

Server Setup

Coqui TTS is based on Python3 so it's recommended to setup a new virtual environment (venv) for the TTS server.

mkdir <TTS directory>
cd <TTS directory>
python3 -m venv .
source ./bin/activate

Then within that environment install the TTS server.

Insallation of the tts python package does not yet work with Python 3.10. See the Coqui TTS issues page for more information.

pip install pip --upgrade
pip install tts --upgrade

Running TTS server

To run the server we need to know two things:

  1. Whether we have a CUDA enabled GPU. Synthesizing voice is significantly faster when run on a CUDA enabled GPU compared to a CPU.

  2. Which TTS model to use.

Running tts --list_models within the venv shows the TTS models available in the current release.

Example output:

tts_models/en/ek1/tacotron2
tts_models/es/mai/tacotron2-DDC
tts_models/fr/mai/tacotron2-DDC
tts_models/de/thorsten/tacotron2-DCA
...

Within the venv we can now start the TTS server by running:

tts-server --use_cuda=false/true --model_name *modelNameFromList* 
`

Example commands:

  • English: tts-server --use_cuda=true --model_name tts_models/en/ek1/tacotron2

  • German: tts-server --use_cuda=true --model_name tts_models/de/thorsten/tacotron2-DCA

By default a Coqui TTS server uses the best vocoder for the selected TTS model. However you can override the default using the --vocoder_name parameter when starting your server.

Once the TTS server is running you can test it by opening http://localhost:5002 in your browser and try synthesizing a test sentence.

Mycroft Configuration

After your TTS server setup is finished you can configure Mycroft to use it with the same configuration as Mozilla TTS.

Responsive Voice

Note: This is a Community provided TTS plugin and is not controlled by Mycroft AI. The code in this plugin has not been reviewed by the Mycroft team. We strongly recommend reviewing any code you intend to install from outside Mycroft's official channels.

Lifelike human digital voices from ResponsiveVoice.org.

Installation

mycroft-pip install ovos-tts-plugin-responsivevoice

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

See the plugin's Github repository for suggested configurations:

https://github.com/OpenVoiceOS/ovos-tts-plugin-responsivevoice#configuration

SpdSay

A common high-level interface to speech synthesis from Free(B)Soft.

Software Setup

Install the speech-dispatcher package using your systems package manager. For example: sudo apt-get install speech-dispatcher

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config set tts.module "spdsay"

Yandex SpeechKit

Speech services from Yandex, one of the largest cloud platforms in Russia.

Account Setup

  1. Register an account at Yandex.

  2. Create billing account: https://cloud.yandex.com/docs/billing/quickstart/#create_billing_account

    You can activate a free trial period in the console.

  3. Create first "folder" in cloud.

  4. Create service account for you Mycroft instance with role editor: https://cloud.yandex.com/docs/iam/operations/sa/create

Mycroft Configuration

Using the Configuration Manager we can edit the mycroft.conf file by running:

mycroft-config edit user

To our existing configuration values we will add the following:

"tts": {
  "module": "yandex",
  "yandex": {
    "lang": "en-US",
    "api_key": "YOUR_API_KEY",
    "voice": "oksana", #optional
    "emotion": "good" #optional
  }
}

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