· 5 min
When a sweep is justified
Requests almost always arise around a sensitive moment: a negotiation, litigation, a change of leadership, or the leak of information that had only circulated in a small meeting.
That last signal is the most telling. When something known to five people surfaces outside, the possibility of a listening device deserves to be ruled out properly.
How a sweep is carried out
The work combines two approaches. A radio spectrum sweep looks for emissions characteristic of an active device. The physical inspection, which takes longer, covers furniture, sockets, light fittings, false ceilings and objects recently brought into the room.
The physical part is essential, because the hardest devices to find do not transmit continuously. A recorder storing locally stays invisible to a radio sweep.
What a sweep does not guarantee
A sweep establishes a finding at a point in time. It does not protect against a device introduced the next day. That is why the report always includes hardening recommendations: access control to the room, management of items brought into meetings, discipline around phones.
One misconception is worth dispelling: a phone left on the table during a confidential meeting is a far more common and mundane risk than a microphone hidden in a wall.
Discretion is part of the service
A sweep announced internally loses much of its value. Engagements often take place outside working hours, without prior notice to staff, and the debrief is verbal before anything is written.