For the past 4-8 weeks audio quality on my landline has been extremely poor. I mainly use my landline to help care for elderly relatives with somewhat impaired hearing, so the kind of interference described below is a serious issue.
Basic fault: a loud buzz as soon as the the line is open.
Details:
- During calls, it seems as if some kind of noise-suppressor or gain control is being applied to the audio signal. If there is absolutely no sound via the handset at either end of the call, then the buzz becomes very loud. As soon as there is any sound at either handset the buzz is somewhat suppressed: but the cut-off (or noise suppression) is crude and the voice of a caller can be clipped in the process. The buzz surges up in volume during the slightest period of silence during a call.
- The symptom is the same regardless of whether the caller on the other end is using a mobile or other kind of handset.
- For the landline, I normally use a Panasonic cordless array: a base station plugged into the master socket and two satellite charging cradles. There are no wired phone extensions in the property beyond the master socket. The faceplate of the master socket was replaced by BT engineers in 2023 in response to a different issue.
- There have been no changes to comms wiring or equipment in the property that coincide with the deterioration in landline quality.
- To test: I have disconnected the cordless array and made calls using an old-school analogue telephone plugged directly into the master socket. With this set-up, the buzz and the gain control/noise suppression effect is still present, suggesting that the buzz is not particular to the telephone apparatus.
- At some point in recent months a BT engineer has carried out work at the utility pole supplying the physical line to the property, apparently installing a new fibre connection point. I am not sure if the deterioration in landline quality exactly coincided with that work, but it's close, in time.
