Any studio that processes phone calls needs hardware to interface with phone lines. 
This device, traditionally called a Hybrid, filters, separates and provides gain adjustment and call control to more easily allow for recording or broadcasting “phoners”.
As telephone companies are shifting from traditional phone lines to Voice-over-IP (VoIP) systems, the devices that performed this job in the past are becoming outmoded. Broadcasters need a VoIP hybrid to ensure on-air and recorded phone calls sound as good as possible.
A dual-line hybrid, VH2 connects two VoIP lines for individual broadcast or flawless conferencing. VH2 prevents echo and distortion, and automatically adjusts caller audio to a uniform level, leaving you with a result that’s clean and clear. Plus, VH2 uses only VoIP phone lines, saving you money and increasing functionality. VH2 can even connect to many VoIP PBX systems.
Easy Hookup
VH2 can be configured in several ways to be compatible in environments where the studio has different telephone connection arrangements. Dual or single input and outputs can be selected, and AES3 or analog audio I/O can be chosen. VH2 can be configured for callers to hear each other, or be isolated depending on the needs of the studio.
On-Hold Inputs
VH2 offers a pair of audio inputs for callers “on-hold”. This allows for listeners to hear your programming while they are waiting to be put “on-air”.
Consistent Audio Levels
Selectable automatic gain control (AGC) maintains a uniform audio output, even when the caller signal varies widely. Also, selectable caller ducking lowers incoming caller audio, so local talent remains in control.
Companion Phone
When configured with its companion phone (the Polycom IP 331), VH2 does even more. Calls can be answered on the handset and easily transferred back and forth to VH2, just like a traditional telephone hybrid. And the companion phone supports caller ID and outbound calling.
Status Indication
VH2 is outfitted with front panel controls and status indicators so it can be used out-of-the-box. Front panel buttons can also be remoted via the rear panel connector, so your console buttons can trigger its functions.

 
Features

• Prevents echo and other artifacts
• Supports normal phone calls (G.711) and wideband phone calls (G.722)
• Allows for caller ID, outgoing calls, screening, and post-air management using companion VoIP phone set
• Set up via easy-to-use web based configuration page