From Hillstone Software:
VoiceComPro is a voice communication application for PCs running Windows platforms. VoiceComPro is designed for voice communication between PC VoiceComPro applications (terminals) on local LAN. VoiceComPro behaves like a push to talk intercom. Once several (at least two) VoiceComPro applications on local LAN become aware of each other, the user can push and hold a key or a button corresponding to the desired remote VoiceComPro terminal and start talking. The voice is reproduced on the addressed remote VoiceComPro terminal. It features push to talk voice communication between up to 40 PCs on the LAN, address and talk to an individual terminal or talk to all (broadcast), and auto detect VoiceComPro terminals on the LAN.