Text to read, do not need to be phonetic
Language code with BCP 47 convention (e. g. "en-US" for English with an American accent)
Optionalrate: number
Reading rate
Optionalpitch: number
Pitch value
Optionalvoice: string
Optional voice, the result will depend on the browser used
Optionalconvert_to_phonetic: boolean
Whether to convert to phonetic first
Read a text aloud, may parse the text to get a phonetic version.