While wearing your headset, lift the handset from the telephone. If you do not hear a dial tone, you will have to configure the amplifier with your telephone.
To View Your Configuration Settings:
Remove the plastic cover on the left side of the amplifier. Most phones will use setting 6 on the MX10 or setting 5 on the M10, M12, and M22.
To Change the Configuration Setting:
Guidelines for Configuration Settings:
1 = Carbon phones
2 and 3 = Specific phones, such as AT&T Merlin
4 = Electret test setting
5 = Electret with batteries installed
6 = Most phones