Curious about the quiet talk behind the walls? Want to know the contents of the conversation? Whether the conversation involves a loved one or a stranger, or takes place at home or elsewhere, eavesdropping is not a good thing. However, if you still want to continue eavesdropping, here are some ways to eavesdrop through walls in a fairly clear voice. Just make sure you are aware of the risk of the threat of punishment before proceeding.
Step
Method 1 of 4: Using a Glass
Step 1. Prepare a glass
Once you've decided to continue eavesdropping, how do you get started? One way is to use a glass that is attached to the wall. Sound from behind the wall can be heard because you create an acoustic coupling between the wall and the glass, so the sound waves can travel from one side to the other. A glass of fizzy drink or beer is the best choice. Some people who have overheard say plastic Dixie cups can also be used. However, glass can transmit sound better than other materials.
- Try different types and shapes of glasses to see which one works best for eavesdropping.
- If you have an iPhone, download the Amplitude Pro app and attach your iPhone to the glass that is attached to the wall. Not only does this app allow you to hear distant sound sources more clearly, it can also record and save enlarged sounds.
Step 2. Find the place with the clearest sound
Some points on the wall can conduct sound better so it can be heard more clearly than others because it is influenced by the structure and distance from the sound source. Try checking the sound quality, until you find the best place. However, this is sometimes difficult to do, especially if the sound is coming from the roof. If you're too far from the sound source behind a wall, you still won't be able to hear it clearly enough.
Step 3. Stick the glass mouth on the wall
Remember, for this method to work, you'll need to acoustically join the walls and glass together. So, put the mouth of the glass to the surface of the wall. Now, the sound waves will travel from the wall into the glass, making it easier for you to hear.
Once the glass is against the wall, place your ear on the bottom of the glass. Move the glass if you still can't hear clearly
Method 2 of 4: Using Holes
Step 1. Make a small hole in the wall
Another way to eavesdrop through walls is to use holes and plastic membranes. This method was recently discovered by researchers in Japan and South Korea. First, make a very small hole with a drill. You can use a small and long-edged drill.
- Don't expect you to hear clearly enough with just this hole. In fact, holes can actually hinder the transmission of sound.
- Use the time when your neighbors aren't home to drill holes in the walls. If not, they're bound to hear the sound of drilling tools or splintering of the walls falling.
Step 2. Cover the hole with a thin membrane
It is this membrane that allows you to eavesdrop with the hole. Research has shown that if you cover a hole with a thin membrane on one side, sound conduction will proceed almost as if there were no walls blocking it, because the membrane will balance the pressure on both sides of the wall and conduct sound.
Try using common household items, such as plastic wrap. In fact, the researchers did use plastic wrap at first
Step 3. Listen
After punching the holes and attaching the plastic wrap, listen to the sound! If done correctly, you should be able to hear what's going on in the next room clearly.
- To get even better results, combine this method with the first method. Place the glass over the holes and the plastic membrane.
- Be aware that punching holes in the wall runs the risk of causing problems, especially when it comes to confidentiality. Your neighbors may be able to hear the sound of a drill, see bits of wall on the floor and become suspicious. Use this method with care!
Method 3 of 4: Using a Spy Stethoscope
Step 1. Prepare everything you need
The next option is more sophisticated hearing equipment. You can make your own stethoscope or buy one. Ready-made spy stethoscope models can save you time, but cost several million dollars. Unlike ready-made models, making your own spy stethoscope may cost you about or even less than IDR 300,000,00--if you already have a decent enough MP3 player.
- You can usually buy a stethoscope at the pharmacy for IDR 150,000.00. The quality of the stethoscope usually doesn't matter much.
- You will also need a microphone. Stereo microphones are even better, because they are quite cheap, around Rp. 200,000, 00 but they transmit sound quite well, so you can hear quite clear sound easily with the microphone.
- The last device is an MP3 player for recording sound, along with a 3.5 mm stereo Y-adapter cable. This adapter cable is quite cheap, maybe only around Rp. 50.000, 00. While the MP3 player is the most expensive tool if you don't have one at home. This MP3 player needs to be able to record sound, so you may need a newer model (as many older MP3 players can only play music, but not record).
Step 2. Remove the microphone component
You'll need to cut through the center of the microphone to open the cord, separate the top or microphone head, and remove it. Next, insert the exposed microphone into the earpiece of the stethoscope.
The tool you can use in this step is the X-Acto knife. The cut is smooth on the outside of the microphone and reaches the inside. Leave the microphone end with the 3.5 mm cable
Step 3. Remove and reattach the ear piece of the stethoscope
Remove the ear portion of the stethoscope. This step is fairly easy, and you can usually drop it right away. However, don't throw it away afterwards, as you'll have to re-pair it with the microphone.
- Next, gently drill a shallow enough hole the size of a microphone in each ear. The size of this hole must exactly match the microphone, so that it can be plugged in. A drill or grinder can help you drill holes of the right size.
- Glue the microphone inside the earpiece. Apply a small amount of glue around the edge of the microphone and insert it into the hole you just made in the ear of the stethoscope. Reattach the ear of the stethoscope and allow the glue to dry.
Step 4. Connect the stethoscope with the MP3 player
The last step, connect the stethoscope to the MP3 player. Use a Y adapter cable to connect the two. Sound traveling through walls is collected and amplified by a microphone, transmitted to an MP3 player, and recorded or stored.
Plug the stereo connector into the MP3 player, and your spy stethoscope is now ready to go
Step 5. Start listening
First, practice using your stethoscope. Just like using a glass, you may have to experiment a bit to find the right location on the wall or get used to recording sound. However, unless your parapet is double-layered, or has thick insulation, you should be able to hear conversations behind the walls.
Method 4 of 4: Understanding the Consequences
Step 1. Ask yourself:
do you really want to or should you spy on? Overhearing through walls is an act of spying that interferes with private conversations. Before proceeding, ask yourself seriously. Is the risk worth it?
- In a very important situation. In England, for example, a man saved his elderly neighbor from a robbery by hearing his voice from behind a wall using a glass. In such a situation, spying is justified.
- However, sometimes the situation cannot be read clearly. So when in doubt, it's best not to overhear. And if you decide to continue, make sure you know the consequences of this action.
Step 2. Know the laws governing eavesdropping
Eavesdropping is an act that aims to listen, record, amplify, or disseminate parts of a private conversation without the permission of one of the parties involved. Be aware that there may be laws governing this action in your area. By spying or even simply possessing spy equipment, you may be violating the law.
- Your region may enforce one or both parties' permission rules. The consent of either party means that you must obtain the consent of one of the parties involved in the conversation, or it means that you are breaking the law. With both parties' consent, you must obtain permission from both parties involved in the conversation to listen, record, or amplify their conversation.
- For example, the US state of Michigan has a bipartisan consent law--so you must obtain permission from all parties involved to "listen, record, amplify, or share any part of their private conversation." This rule even applies in your own home. Eavesdropping in the state of Michigan is illegal.
Step 3. Consider all the negative consequences
What happens if someone finds out you're eavesdropping? What will you experience? This is a question that deserves some thought, and one that you should consider all the possible consequences, which in most cases can be quite burdensome.
- In Michigan, USA, the fine for unlawful eavesdropping is a maximum of 2 years imprisonment, a fine of up to 2000 US dollars, or both. In California USA, eavesdropping can be classified as a misdemeanor or a felony. As a misdemeanor, you are threatened with a maximum imprisonment of 364 days and a fine of 2500 US dollars, while as a serious crime, you are threatened with a maximum imprisonment of 3 years and a fine of 2500 US dollars.
- Of course, the threat of criminal punishment is not the only bad result you may face. You also risk civil lawsuits for violating other people's privacy, which may cost you tens of millions of rupiah. Even if you escape legal threats, your neighbors may be furious about it.
