Finally, you can call references. Most reputable investigators will provide references upon request. It is legal to conduct surveillance upon a person for legitimate purposes. You must hire a licensed investigator to carry out assignments. It is illegal in all states to record the voice without at least one persons consent.
Many states require all parties to consent to an audio recording.
People often notice clicking on the phone line, sounds in the wall or people knowing information that should not be known. Most of these symptoms don t have much relevance as to the existance of bugs or taps. The only sure way to locate a device is through the experienced use of professional test equipment. Noise on a phone line is usually due to bad connections in wiring and not a tap. A tap is silent if installed correctly.