Listening devices, be they
hidden listening devices or
covert listening devices, are
generally used for audio
surveillance by means of one
way communications. A
listening device can be a
voice activated transmitter or
voice transmitter that starts
operating once it detects the
sound of a persons voice.
When listening devices
are active, they may attach to
a surveillance microphone
connected to a surveillance
recorder, audio transmitter,
or Spy Phone, capturing all
that is said and either storing
the conversation, or
broadcasting it to those who
need to hear the conversation
without being present. |