Indications of Tapped Phone Lines

by Matt Scheer

Wire tapping is becoming more frequent because there are many methods available. People's phone lines are often tapped by thieves looking for identity information. There are ways to keep your information safe, however. First, don't use a portable (cordless) phone, because a number of devices tuned into the same frequency can pick up the conversation. Second, check for tapped phone lines. Finally, hold important meetings in public; don't give out private information over the telephone.


Check the radio and the TV for static or interference. Many phone taps disrupt normal operation of these devices because they use similar frequencies. Check the radio by turning it to "Mono" and then searching the lowest and highest frequencies for squealing noises. Move around the space to check for these noises. If the television gives this option, search UHF channels for interference because these frequencies are closest to some eavesdropping devices.


Listen for abnormal noises on the phone line while having a conversation. Tapped phone lines often create a clicking, static or popping sound because two conductors (the tap and phone line) are coming into contact. Test this with a sound-bandwidth sensor. Hold the device up to the phone while having a conversation. The phone may be tapped if the indicator rises a few times within a minute. Check for noises coming from the phone when its not in use. Some wire tapping devices change phones into a type of microphone and speaker. If the phone makes a dial tone, murmuring or clicking sound, there is a good chance the wire is tapped.

Abnormal Activity

Watch for abnormal activity around the property. A strange van with tinted windows, parked within 500 to 700 feet, may have eavesdroppers inside. Be suspicious of phone repairs that happen without your request. Ask the phone company if they sent the maintenance person. Notice whether any of the furniture or phone jacks are out of place. Somebody may have been inside the property to install a tapping device. This may be true also if there was a burglary at the property, but nothing seems to be missing.

About the Author

Matt Scheer began writing professionally in 2005. His work has appeared in "The Daily Texan" and "The New York Tribune." Scheer holds a B.A. in English and a B.A. in history, both from the University of Texas. He is also a certified Yoga teacher and Web designer.

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  • photo_camera wireless phone image by timur1970 from