I have to use
react-native-tts instead of Expo Speech module because there is a huge difference between default iOS voice Expo uses and the native siri one you can pick.
On iOS, it’s basically just adding
utterance.voice = [AVSpeechSynthesisVoice voiceWithIdentifier:voice]
https://github.com/ak1394/react-native-tts can be used as a reference
Can someone update Speech module to support setting voice or point me to where I can find it to make PR?