| pcm_to_wav | Convert PCM to Wav |
| tts | Text to Speech |
| tts_amazon | Text to Speech |
| tts_amazon_auth | Authorize Text-to-Speech Engine |
| tts_amazon_authenticated | Authorize Text-to-Speech Engine |
| tts_amazon_voices | Text to Speech Voices |
| tts_auth | Authorize Text-to-Speech Engine |
| tts_bind_wav | Bind Wavs together |
| tts_default_voice | Text to Speech |
| tts_google | Text to Speech |
| tts_google_auth | Authorize Text-to-Speech Engine |
| tts_google_authenticated | Authorize Text-to-Speech Engine |
| tts_google_voices | Text to Speech Voices |
| tts_microsoft | Text to Speech |
| tts_microsoft_auth | Authorize Text-to-Speech Engine |
| tts_microsoft_authenticated | Authorize Text-to-Speech Engine |
| tts_microsoft_voices | Text to Speech Voices |
| tts_speak_engine | Speak Enginge for 'knitr' |
| tts_voices | Text to Speech Voices |