Mic Lock Review: The Most Underrated Privacy Tool

Ever wonder whether your device is listening to and recording you even when it’s not supposed to? Ever accidentally butt-dialed someone only for them to hear a conversation that they shouldn’t have heard? Mic Lock is the web-cam sticker equivalent for microphone blocking that is totally underappreciated for protecting your privacy.

Mic Locks are the best, easy-to-use microphone blockers on the market. By tricking your device into thinking there is a microphone plugged in, even if your device tries to eavesdrop, it won’t be able to record anything. Get the original Mic Lock if you need a compact form or get the Mic Lock with SoundPass if you want the versatility of still being able to plug in external headphones or speakers.

I bought two kinds of Mic Locks and have been using them for over six months now. In this article, I’ll talk about my experience using these to block the microphones on my devices, and what I wish I knew before I bought them. I’ll also cover why you might want a microphone blocker and exactly how these Mic Locks function.

mic lock plugged into a laptop

Why Would You Want To Block Your Microphone?

Here are some reasons why you might want to consider blocking your microphone:

  • To have the peace of mind that no one can hijack your microphones and listen to you.
  • To prevent accidental callers (a.k.a. the good old butt-dial) from hearing your conversations.
  • To ensure that your microphone is muted on a conference call.
  • To ensure that your work or school-provided device is not snooping on you as you work from home.
  • To avoid getting advertisements related to your conversations.
  • To protect yourself from targeted attacks if you are a stalking victim, journalist, activist, business executive, federal agent, etc.

You might be wondering, are our devices actually listening to us behind our backs or have I just got my tin-foil hat on too tight?

Whether or not our devices are recording everything we say is actively debated in privacy communities. While there is no smoking gun to prove without a doubt that tech giants like Facebook or Google are listening, many people have had clear experiences where a product is mentioned audibly in their day to day lives and the same product shows up in targeted advertisements online hours later.

Do these numerous experiences prove that they are listening? It’s hard to say. An alternative explanation is that the other inputs used to personalize advertisements are just that good. Tracking your interests through your browsing history, your friends and family, or your location could give the illusion that your phone is listening to you when, by coincidence, the algorithm suggests a product you talked about with your friend. You may not recall any connection to that product besides the conversation, but perhaps your friend was researching it online and was caught in the data drag net, resulting in Google or Facebook thinking you might be interested in the product as well.

Of course, all the tech giants vehemently deny that their products listen to everything we say to improve targeted advertising. Whether or not to believe them is up to you. Just like with the webcam sticker, I say it’s better to be safe than sorry and just block the microphone to remove any doubt.

The majority of us (especially my readers) already block their web cameras with some sort of sticker or cover. I would be disgusted if I found out that someone had hacked my web cam and could see me and my home. However, the idea of someone hacking my microphone just doesn’t have quite the same visceral reaction. If I had to choose, though, I would rather have my web cam hacked than my microphone.

Our conversations have the potential to reveal so much more sensitive information than our cameras would ever reveal. A listening device could reveal your relationships and interests, insider business information, and even the doctor’s appointment you made for that weird rash. Plus, audio data is much easier to process in big batches with speech-to-text software, which could make your conversations searchable in an algorithm or database and reduce the storage size dramatically.

So why have we neglected our microphones? As usual, I think the answer is convenience. A camera is a very straight-forward device to block. No special equipment needed, just use one of the sticky notes that are already sitting in your drawer. When it comes to blocking microphones, however, a sticky note just isn’t going to cut it. We need a consumer-friendly solution, and Mic Lock fits the bill perfectly.

Mic Lock is the best, easy-to-use, fool-proof solution to block your microphones and have the peace of mind that nobody is listening.

How Do Mic Locks Work?

Mic Locks don’t physically disable the microphones on your devices. Instead, they rely on your operating system to automatically switch audio inputs when you plug-in your own external microphone. When you insert a Mic Lock, your phone or computer thinks you are actually plugging in a microphone, but it won’t receive any audio signal.

Understanding the above point is critical to understanding under what conditions a Mic Lock might fail to protect you. It would take malware that’s quite advanced and that has obtained escalated privileges to defeat a Mic Lock because the program would have to be able to choose which microphone it activates. Then, the program could choose to activate your internal microphone rather than the external device.

For the average person, malware that could defeat microphone blocking is not going to be an issue. If you have a very advanced threat model where this kind of an attack is a concern, then you might want to resort to removing your device’s internal microphones altogether. In my article on personal privacy threat modelling, I would say that this threat would fall under tier three (governments and targeted attacks).

mic lock compared to headphone connections

You can see exactly how the Mic Lock is different from regular headphones with no microphone in the image above. Notice the number of conductor rings on the 3.5 mm connector. The tip and the first ring is where the left and right audio signal comes through. The Mic Lock, however, has a second ring, which is for the microphone signal. This extra ring tells your computer that this device is supposed to have a microphone, so your operating system will switch the audio input. Of course, there is no microphone in the Mic Lock, instead the microphone signal is connected to ground, so no audio will be recorded.

Original Mic Lock Vs. Mic Lock With SoundPass

Something that I didn’t exactly think through all the way when I bought my first Mic Locks is that, when you have the device plugged in, your microphone AND speakers will be blocked. So for example, when you are on a conference call and want to ensure that you aren’t accidentally unmuted, but still have to actually listen to the call, you’ll want to get the SoundPass version.

original mic lock and mic lock with soundpass

The Mic Lock SoundPass will block your microphone while also allowing you to plug in a pair of headphones or speakers. I ended up purchasing the SoundPass version after my first purchase of the original blockers. I’m actually glad I have both now, since each design works best for different use cases.

Get the original Mic Lock if:

  • You never use the speakers on your device.
  • You want to use Mic Lock on your mobile device and need a compact design.
  • You are willing to take out the Mic Lock whenever you need to use the microphone or speakers.

Get the Mic Lock with SoundPass if:

  • You want to block the microphone and hear audio output at the same time (conference calls, watching video, listening to music, alarms and notifications.)
  • Your device is stationary (like a desktop), so compact design does not matter.
  • You plug-in headphones or external speakers all the time anyway.
  • You can only afford one Mic Lock and want the most versatility for your money.

Do Mic Locks Work On All Devices?

Only have a lightning port or USB-C port? There is a Mic Lock for you as well as those still using the traditional 3.5 mm audio jacks. Because of this, Mic Locks will be compatible with nearly all devices. They even have both the compact and SoundPass versions with lightning and USB-C ports.

There are still a couple of things to check to determine if a Mic Lock will work for your device. Namely, checking your case dimensions and making sure your audio input switches automatically.

Make Sure Your Phone Case Leaves Enough Space

Make sure any case that you use for your device provides enough room to accommodate a Mic Lock. This is more likely to be a problem on a phone but applies to any device that you put into a case. (Maybe a laptop case, or a purse?) The dimension details for both Mic Locks are shown in the image below.

mic lock dimensions

Now, I did not have calipers to measure this with extreme precision, instead I just used a normal ruler. I estimate the precision of these measurements to be about plus or minus 0.5 mm. I measured the diameter of the original Mic Lock to be 9 mm, while the SoundPass version was slimmer at 6 mm. The distance that the original Mic Lock sticks out when plugged into a device was 17 mm. The distance that it sticks out really doesn’t bother me at all.

Check If Your Linux Device Switches Audio Inputs Automatically

Are you the type of techie person that likes to try out weird Linux distributions and explore beyond the easy-to-use Windows, macOS, or Ubuntu? If so, you should double check to make sure your device automatically switches your audio input when you plug in an external microphone before you purchase a Mic Lock!

It’s easy to check. Just go to your audio settings and find where you can select which audio input and output to use. Without any external devices plugged in, set your device to use your internal microphone and speakers. With the dialog still up, plug in a pair of headphones with a microphone (or just a microphone if you have one) and see that your audio input switches to the headphone input automatically.

This is something I wish I would have checked before I bought my Mic Locks. I was using Manjaro Linux with KDE and found that my audio input wasn’t switching automatically, which made the Mic Lock more inconvenient to use. (It’s not Mic Lock’s fault, though.) It doesn’t make them totally useless, I just had to remember to switch my audio input when plugging in the Mic Lock.


The peace of mind you get by using microphone blockers is indescribable. No longer will you have to worry if that sketchy app on your smartphone is listening to you in the background, nor will you have to worry about accidental calls creating awkward situations.

Mic Locks are such a simple, easy-to-use solution, I honestly wish I had bought them sooner. I hope this article doesn’t come off like an ad! I just really do love the things. (And yes, paid my own hard-earned money for them.)

If you’d like to support the blog (with no additional cost to you!), use our affiliate links when you’re ready to purchase your own Mic Locks. For your convenience, here are all the different types of Mic Locks on Amazon:

Port TypeOriginal (Compact)With SoundPass
3.5 mmAmazon linkAmazon link
USB-CAmazon linkAmazon link
LightningAmazon link