Telecom Audio offers three types of interfaces for computer sound card / telephone applications:

Phone Port
Phone Line Simulator
Connect a wired or wireless telephone to your PC sound card. Use your telephone to talk on the web.

Voice Port
Telephone Handset Tap
Connect your telephone to your PC sound card for easy record and play. From phone to PC and back again.

Voice Over
Audio In Your Ear
Play sound card or CD audio into your telephone handset or headset. Listen while you work.