Telephone Hybrid

You also need a Telephone Hybrid Interface, to join the console with audios coming from phone calls.
This is important if you want to take phone calls while you are on-air.

In simple terms, a Hybrid is an interface that connects two-wire phone lines into input and output XLRs. These XLR connectors are plugged into an audio console or I/O node.

Many Hybrids also contain echo cancellation and an automatic equaliser.