Gets available preview voices for the speech provider selected in the Project settings.
Supply the API Key in the HTTP-Header
The Accept header specifies the media type that the client expects in the response. Available options: application/json, application/hal+json, application/xml, text/xml, text/csv. The default value is application/json.
application/json, application/hal+json, application/xml, text/xml, text/csv Project id from which it will get the settings
Returns the available audio preview voices