What is the voltage of a landline telephone?

How to connect Wi-Fi headset to landline telephone. ?

• How can I connect Wi-Fi (wired) headset to land line telephone? I think I need: On one side need telephone jack - This will go in my telephone instead of receiver. (So, Output will be telephone jack.) On other side need two female 3.5 mm jack - In these, two wires from my Headset will go in. If this is right, where can I get it, what is it called? Any other solution welcome.. Please help. Thanks Nitin

• Answer:

  you need to convert the phone to voice. the phone system works on current loop, 20ma loop at -48v. voice is transmitted as a change in current. your wired headphones work on voltage, the voice data is a changing voltage. you need to convert a change in current to a change in voltage. The simplest way to do this is with a network of capacitors and inductors. another way is with a cheap junky telephone. the type that uses a speaker and a microphone. rip the handset apart and modify it.