If you use a headset for both telephone and computer, GN Netcom has you covered, with
the GN 8050-TCA. Not only does the GN 8050-TCA work with just about any phone with
a modular connector, it also plugs right into any Sound Blaster-compatible PC and lets you
switch between your phone and your computer with a single click.

Headset solutions are becoming more and more common in conjunction with a PC for various desktop utilities such as web telephony, voice recognition and voice dictation.

In response to this growing demand, we have designed the GN 8050 TCA. With the built-in PC/telephone switch, you simply use one headset for both the telephone and PC. GN 8050 TCA is compatible with most audio devices.

Further details:
GN Jabra 8050-TCA Headset Amplifier (PDF)