Hello Dean & Welcome to Just Answer,
I'm Greg and will do my best to assist you today.
Sorry to hear of any issue you are having with your phones.
To help you with this issue, may I ask:
1) The FULL Model Number of the phone system you are working with? Since this is a cordless system, that model should be printed on a sticker on the bottom or back of the MAIN base and START with KX-TG, but NOT have an "A" before the numbers (that is for the Cordless Handsets only).
2) How many TOTAL cordless handsets do you have with this system, and of more than one, do ALL handsets have this issue?
3) What phone service provider (phone company) you have for this phone line?
4) If you have ANY other devices that are NOT part of the Panasonic system (phones, fax, etc.) attached to this same phone line(s) and if so, are they working properly WHEN the Panasonic units can't be heard?
Please REPLY ONLY on this page.