On 2/5/2017 2:58 PM, home owner wrote:
In 2005, I bought a Panasonic DECT 6.0-Series Cordless Phone System with Answering System (KX-TG1033S) which includes 3 handsets, 1 base, and 2 chargers. In September 2015, I installed Panasonic HHR-75 (700 mAh) AAA Ni-MH Rechargeable Batteries in each handset.

When an incoming call goes to the answering system, a buzzing sound occurs.
The buzzing sound is also heard when I listen to recorded messages.

What is causing the buzzing sound?
How can I resolve it?
Or would it be best to buy a new phone/answering system?

Previous non-answers are reason #2 Usenet might be dying; you all know
reason #1.

That said, I have a Panasonic DECT 6.0 phone and get 60 cycle hum at
times. This is mostly when when just using the phone. I've found that
the base was next to a computer amplifier/speaker. If I move it just a
few inches from the amplifier/speaker, hum goes away. Previously, I've
also heard hum in the computer speakers, when the phone base is close to
the speaker with the amplifier. I know it's a bit different than OP,
but maybe not completely?