In a shared room, someone always wants it louder and someone always wants it quieter. When each person hears the same audio on their own device, everyone sets their own level — and the person who needs it loud finally can.
One person turns their device up loud, another keeps it low, a third listens on headphones — and it's all the same feed, in sync. Nobody blasts the room, and the person who needs it loud isn't asking everyone else to put up with it.
A phone, a tablet, a laptop — join the room and it's a personal listening device. Plug in wired headphones for private, boosted sound with none of the room noise.
It replaces rented FM or IR assistive-listening receivers and their bag of chargers with the devices people already carry in their pockets.
A family movie night where one person needs it loud and the rest don't. A meeting where the back of the room can't hear. A packed service with an overflow area. Send one feed to everyone's device, in sync, each at their own comfortable level.
No hardware to hand out, no chargers to keep track of, no compromise on volume. If a person has a phone with a browser, they have a receiver.