ReadonlydefaultThe default read-only property of the SpeechSynthesisVoice interface returns a boolean value indicating whether the voice is the default voice for the current app (true), or not (false.)
ReadonlylangThe lang read-only property of the SpeechSynthesisVoice interface returns a BCP 47 language tag indicating the language of the voice.
ReadonlylocalThe localService read-only property of the SpeechSynthesisVoice interface returns a boolean value indicating whether the voice is supplied by a local speech synthesizer service (true), or a remote speech synthesizer service (false.)
ReadonlynameThe name read-only property of the SpeechSynthesisVoice interface returns a human-readable name that represents the voice.
ReadonlyvoiceThe voiceURI read-only property of the SpeechSynthesisVoice interface returns the type of URI and location of the speech synthesis service for this voice.
The
SpeechSynthesisVoiceinterface of the Web Speech API represents a voice that the system supports. Every SpeechSynthesisVoice has its own relative speech service including information about language, name and URI.MDN Reference