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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 in order to obtain a (free) API key. Without an API key, this package will not work properly.

See the documentation here:

Getting an API key

You can get a TTS API key here: The API you need to get one from is Cognitive Services, Speech.

  1. Create an Azure account
  2. Go to If that works, skip to step 5.
  3. Go to
  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()) {
  tuneR::play(mp3, player = "play")