Echo plugs are plugged into the hands-free jacks of wireless telephones to facilitate
testing. One echo plug has a pin and a circuit. The pin is physically compatible
with the hands-free jack of a wireless telephone. The pin has a speaker connection
and a microphone connection. The circuit couples the speaker connection to the
microphone connection. In operation, this echo plug receives a signal from the
speaker connection of the hands-free jack and transfers the signal to the microphone
connection of the hands-free jack. Another echo plug has two pins and a circuit.
The pins are physically compatible with the hands-free jack of a wireless telephone.
The first pin has a speaker connection, and the second pin has a microphone connection.
The circuit couples the speaker connection of the first pin to the microphone connection
of the second pin. In operation, this echo plug receives a signal from the speaker
connection of a hands-free jack in a first wireless telephone and transfers the
signal to the microphone connection of a hands-free jack in a second wireless telephone.
