Perhaps invest in a keyboard. I think there's also a speech to text function on the PS4 as well, i'm not sure i don't have mine on. Either way, you can get a cheapo usb keyboard for like 10-20 dollars, and if you're running out of USB ports, you can buy a usb hub for like 5-10 dollars.

Also, when people barge in when i'm in the middle of a boss fight, i make them wait, or at the very least i will continue to fight while talking to them.