// Core Service

Listening device detection

If someone knows what was said in a room they were not in, that is worth taking seriously. Audio devices are the hardest category to find, because the most effective ones transmit nothing at all while they are working.

// The three device types

RF transmitters broadcast audio live on a radio frequency. Found by full spectrum RF analysis.
GSM devices use the mobile network and work anywhere with coverage. Found by cellular band analysis.
Passive recorders store audio to internal memory and emit nothing. Found by non linear junction detection.
Compromised devices smart speakers, phones and systems with legitimate microphone access retained by someone else.
Written report recording every area cleared and any device recovered.

02 8551 8883 · safesweep.com.au

Detection

RF · GSM · NLJD

Range

10 MHz – 12 GHz

Coverage

Australia wide

NATO NCAGE

Z1NK9

// 01

Why audio is harder to find than video

A camera has a lens, and a lens is a physical certainty that optical detection can exploit. A microphone has no equivalent tell. It is a small component with no distinctive optical or thermal signature.

Worse, the most damaging class of audio device is the one that records locally. It sits inert, capturing everything, transmitting nothing. There is no signal to detect while it is working. It is collected later, or retrieved when the person who placed it has access again.

This is the category that non linear junction detection exists for. It transmits a signal and reads the harmonic response that semiconductors produce. A circuit board answers whether or not it has power, which is how a switched off recorder inside a cushion or a wall cavity is located.

// 02

Where audio devices are placed

Rooms where decisions happen

// Priority targets

Bedrooms, kitchens, home offices, boardrooms and meeting rooms. Placement follows conversation, not floor plan.

Inside furniture and fittings

// Concealment

Behind wall plates, under desks, inside sofas and cushions, within light fittings and inside appliances with a power source.

Objects that travel

// Mobile

Bags, jackets, gifts, children's belongings and vehicle interiors. A device that moves with you hears everywhere you go.

Existing smart devices

// Retained access

Speakers, TVs, security systems and baby monitors configured by someone who still holds the account.

// 03

What to do before the sweep

If you suspect audio surveillance, change where you have sensitive conversations before we arrive, not after. Discussions with a lawyer, a support worker or about your plans should happen outside the property and away from your vehicle until the space is cleared.

Do not discuss the suspected device inside the space, and do not search for information about detection on a device you are unsure of. If the concern relates to legal proceedings, tell your solicitor early, because it affects how they communicate with you.

// FAQ

Common questions

Can you detect a listening device that is switched off?

Yes. Non linear junction detection identifies the semiconductor components inside electronics regardless of power state. This is the only reliable way to find a recorder that stores audio locally and transmits nothing.

Can a bug work without wifi?

Yes. GSM devices use the mobile phone network and work anywhere with coverage, with no connection to your wifi at all. Passive recorders need no network whatsoever.

How do I know if I am being listened to?

The most reliable indicator is behavioural rather than technical. Someone referencing the content of a private conversation, a phone call, or a discussion with a professional that they had no legitimate way of knowing about. Trust that signal and get the space checked.

Should I have sensitive conversations in my car instead?

Not unless the vehicle has been swept. Vehicles are a common placement for both audio devices and trackers, and a car is an acoustically excellent place to record. Step outside and away from both until the sweep is done.

Book an audio sweep

If conversations are getting out, we will find the reason or confirm the space is clear.