The "Opening" (default since iOS 7) and "Reflection" (default for iPhone X and later) are the most recognizable [35].
While on a call, you can play audio from any app (like Music or a soundboard), and the recipient will hear it mixed with your voice [15]. Watch how to enable audio sharing during your live calls: iphone_call_sound_effect
Features like Voice Isolation or playing audio files into a live call. 📞 Playing Sounds During a Call The "Opening" (default since iOS 7) and "Reflection"