In a noisy environment, you definitely won't be able to hear them, but if you're in a place where you can turn off lights, radios, televisions and other sources of sound, you may be able to hear a camera activate.
Unfortunately, the above methods aren’t foolproof — but don’t give up just yet.
Mirrors can be suspicious, too, because you won't be able to see a camera hidden behind them.
Make your search easier by using a camera-detecting app on your smartphone.
Now that tech is smaller and cheaper than ever, it's become easy to install cameras almost anywhere.
In fact, once you start looking, you may realize that cameras are everywhere: on traffic signals, in parking lots and inside stores.
With either app, you'll need to be within a few feet of a camera to spot it.
The advantage of these apps is cost and accessibility.
These cameras have plenty of perfectly legitimate uses.
They can provide security in public spaces and prevent theft in businesses.
Browsing Amazon for hidden cameras is a little disconcerting.