This could be helpful to certain groups of people like the elderly or otherwise impaired to get important messages heard.
In my opinion this could also be helpful to people which are in areas where only spotty reception is possible. Sending a voice message could be more fruitful than trying to actually call.
This could be fine grained with:
- Autoplay when new audio received in chat/channel/group.
- Playback should be started by user, but will stop only when all audio is played out.
- Endless cycle mode
What do you think?