Push to talk or "PTT" is a way of communicating with others by pressing a button or switch on a device.
 Destiny has developed a method of Push To Talk that streams audio via the internet that is very clear.
Clear Internet Streaming Audio - ClearISA

Repeaters are limited in distance, ClearISA works worldwide!
You can combine your electronic reporting, GuardTour and communications devices (less equipment costs)
ClearISA works off of your data connection. No service plan available? ClearISA can work of a WiFi connection!
Available for Windows computers, Android and iOS devices, and all can communicate with each other.
This is TRUE STREAMING AUDIO in REAL TIME, not a recorded message that is played back after your done recording
Each company has its own multi channel private network, not accessible by outsiders, only those with issued user/pass
Most employees own a smart phone - we have apps for both Android and iOS (no equipment to purchase)