When starting an audio-only call, the app routes audio through the loudspeaker (speaker mode), exactly like a video call — just without video. There is no earpiece / receiver mode, no way to use the top speaker like a normal phone call.
Expected behavior
- Audio-only calls should use the earpiece (receiver / top speaker) by default, like a normal phone call
- Video calls should use the loudspeaker by default
During an audio call, when the phone is brought to the ear:
- the screen should turn off (the proximity sensor should be used to prevent accidental touches)