The laser bounce listening system consists of a laser beam (usually an infrared beam) and a specialized receiver. The laser is bounced off a window and captured by the receiver. The window will vibrate slightly from voices inside the room and the reflected beam will modulate with these vibrations. The infrared detector will detect this modulation and produce an electrical signal. This waveform can be amplified and converted to sound. The major bonus for the eavesdropper is that (s)he does not need access to the premises. The easiest way to detect lasers is with infrared-sensitive equipment.