Available on js
utterance:SpeechSynthesisUtterance
@:optionaloptionalname:Null<String>
error:SpeechSynthesisErrorCode
@:optionaloptionalelapsedTime:Null<Float>
@:optionaloptionalcomposed:Null<Bool>
@:optionaloptionalcharLength:Null<Int>
@:optionaloptionalcharIndex:Null<Int>
@:optionaloptionalcancelable:Null<Bool>
@:optionaloptionalbubbles:Null<Bool>