What Are the Causes of Feedback on a Landline Phone?

By Helen Akers

Long periods of rain might cause damage to telephone wiring.
i Thomas Northcut/Photodisc/Getty Images

Feedback on a landline may come in the form of static, unexplained noises or crosstalk. Faulty outside or inside wiring are some of the main causes of these types of noises. Interference from other electronic devices as well as inclement weather contribute to phone line static. In some cases, the phone equipment that is being used is faulty or needs to be charged.

Outside Wiring

Damages to the phone wiring that is maintained by the telephone company might cause noises and static on landline phones. Wiring that is the responsibility of the phone company usually begins at a network interface device (NID) or demarc located near the outside of a building. The wiring runs from the NID and may be underground or hung in mid-air from telephone poles. Inclement weather conditions may damage this wiring. Damage might also occur from normal wear and tear, routine inspections or from outside workers who come in contact with the wiring by mistake.

Inside Wiring

There are some cases where feedback on landline phones is caused by faulty inside wiring. The inside wiring is typically the responsibility of the owner or resident of the building where service is being provided. This wiring runs from the customer section of the NID and into the building. Damaged phone jacks and phone cords are one of the main culprits of noise and static on phone lines. The damage may occur within the wiring, connectors or both.


Using several devices on one phone line may result in feedback on a landline phone. For example, using a splitting device to connect both a modem and telephone set into one phone jack could occasionally result in static or unpleasant noises. Since both devices rely on electrical currents to operate, they might experience cross interference. One of the ways to test for multiple device interference is to disconnect all devices that are using the phone jack, except for the telephone.


Occasionally defective phone equipment will result in static or unexplained feedback. Cordless phone sets that rely on a battery charge are a good example. If the battery is not charged fully or is running low, it may cause a large amount of static and even poor voice quality. Allowing the handset to fully charge usually resolves the issue. If the noise and static persists, the phone equipment may have a defective part. Plugging another phone device into the phone jack will reveal whether there is a problem with the equipment.