Have you ever wanted to or really needed to hear a conversation in another room or location? Well now you can and it is simple and easy. All you need is your cell phone or another cell phone that you don't need.
First you will need a cell phone and a cell phone headset that plugs in. (For short term listening you could use a Bluetooth headset)
Now you have a couple different options on how you can spy using your cell phone. I recommend a plug in headset for your phone.
What you need to do is go into the settings on your cell phone and change the answer mode to Auto, so that when you ring your phone it automatically answers. Most phones will only work in Auto answer, if you have the headset plugged in.
The next step for long term surveillance is to disable the screen on your phone, you should be able to do this by going into your settings. Also disable the ringer and vibrate and put your phone on silent.
IF your going to do long term surveillance you will need a phone charger for the phone. With Auto answer turned on and the headset plugged in, you can hide the phone behind a couch or chair or somewhere that it won't be noticed plugged into a wall charger.
Now test your phone by calling it and having the tv on or someone talking in that location and see how well it picks up sounds. Experiment with location of phone.
The simple Bluetooth method for short term listening. Set your Bluetooth headset turned on anywhere in the location of your choosing. (preferably hidden) Make sure that your phone is paired with the Bluetooth headset. Go ahead and call your phone and see how far away you can go and still hear the other room through your Bluetooth headset. Usually you can be up to 3 rooms away. With the Bluetooth method you don't need to have your phone on auto answer.
You can always leave your phone in one location and the Bluetooth headset in another and have it on Auto answer. That way you could leave the area and still pick up the conversation.
Things You'll Need
Headset (preferably not Bluetooth)
Cell phone charger (optional)
If doing long term surveillance I recommend using a prepaid service such as virgin mobile or cricket where you can get unlimited talk time. There is a way to wire your phone into a wall socket or computer outlet. (I will try to bring these methods soon, or they can be researched online)
If your not going to be at a location for a long time or don't want to go back to that location, use an exposable phone. (prepaid phone) Be careful and don't break the law