Please check the below for Languages Supported for Salesforce Service Cloud Voice.
Chat message content
Amazon Connect provides full Unicode support. You can chat with customers in any language of your choice.
Amazon Transcribe
Amazon Transcribe streaming transcription enables you to send an audio stream and receive a stream of text in real time. The API makes it easy for developers to add real-time speech-to-text capability to their applications. For supported languages, check https://docs.aws.amazon.com/transcribe/latest/dg/what-is-transcribe.html.