mscstts Package:

The goal of mscstts is to provide an R Client for the Microsoft Cognitive Services Text to Speech REST API, including voice synthesis. A valid account MUST be registered at the Microsoft Cognitive Services website https://azure.microsoft.com/en-us/free/cognitive-services/ in order to obtain a (free) API key. Without an API key, this package will not work properly.

See the documentation here: https://docs.microsoft.com/en-us/azure/cognitive-services/speech-service/overview

Getting an API key

You can get a TTS API key here: https://azure.microsoft.com/en-us/free/cognitive-services/. The API you need to get one from is Cognitive Services, Speech.

  1. Create an Azure account
  2. Go to https://portal.azure.com/#create/Microsoft.CognitiveServicesSpeechServices. If that works, skip to step 5.
  3. Go to https://portal.azure.com/#home
  4. Click + Create a Resource
  5. Search “Speech”
  6. Hit + Create
  7. Should be able to create an F0 account (which is free - see below) if you hit the pricing tiers

Setting up your API key

You can set up your API key in a number of ways (where XXX is your API key):

  1. Edit ~/.Renviron and set MS_TTS_API_KEY = "XXXX"
  2. In R, use options(ms_tts_key = "XXXX").
  3. Set export MS_TTS_API_KEY=XXXX in .bash_profile/.bashrc if you’re using R in the terminal.
  4. Pass api_key = "XXXX" in arguments of functions such as ms_list_voices(api_key = "XXXX").


You can install mscstts from GitHub with:

# install.packages("remotes")


if (ms_have_tts_key()) {
  res = ms_synthesize(
    script = "hey, how are you doing? I'm doing pretty good",
    output_format = "audio-16khz-128kbitrate-mono-mp3")
  tmp <- tempfile("example", fileext = ".mp3")
  writeBin(res$content, con = tmp)
  mp3 = tuneR::readMP3(tmp)
testthat::expect_true(file.size(tmp) > 50000)
if (interactive()) {
  player = tuneR::getWavPlayer()
  if (.Platform$OS.type == "windows" && is.null(player)) player = NULL
  if (.Platform$OS.type != "windows" && is.null(player)) player = "play"
  tuneR::play(mp3, player = player)