Can Your Speaker Be Turned Into a Listening Device? The Shocking Truth


Just when you thought it was safe to blast your favorite tunes through your speaker, a chilling statistic comes to light: a recent study shows it’s possible for hackers to manipulate and turn your speaker into a listening device that spies on you.

Headphones can work as microphones since they use the same components but in reverse. Malware can modify PC audio chipsets to convert headphone jacks to mic jacks, allowing connected headphones to serve mics for eavesdropping.

This article will further explore the question of whether our speakers can be turned into eavesdropping devices. It’ll shed light on the potential privacy risks associated with speakers and provide tips for securing your device to ensure your privacy.

Wireless speaker on a white background

The Potential of Speakers as Listening Devices

Behold, in the hands of hackers, a speaker’s capability is no longer limited to emitting sound. It can turn the tables and listen in on conversations like a sinister spy. This has raised concerns over privacy and security, especially given that speakers are often found in private spaces such as homes, offices, and hotel rooms. 

Let’s take a look at the various means that hackers can turn your speakers into a malicious eavesdropping device: 

Malware-Based Audio Capture:

The most common way to transform speakers into spying devices is through the use of malware. Malicious software can infiltrate a user’s computer, smartphone, or other devices with integrated speakers and microphones and exploit those systems to record audio.

To achieve this, attackers typically target known vulnerabilities in operating systems or applications or use social engineering techniques to trick users into installing malware. Once inside the system, the malware can enable audio capture through the built-in microphone and even potentially repurpose the speakers as microphones, which leads us to our next point.

Turning Speakers into Microphones:

Speakers and microphones essentially operate on similar principles: converting audio waves into electrical signals or vice versa. In the case of speakers, they play sounds by vibrating a diaphragm to create sound waves. Microphones, on the other hand, detect sound waves and convert them into electrical signals. So both of them have the same physical components, but they use them in reverse.

Basic illustration shows that a speaker and a microphone are just inverses of each other.

A basic illustration shows that a speaker and a microphone are just inverses of each other. Image courtesy of “Turn Speakers to Microphones for fun or Profit”

The fact that speakers and microphones have similar physical components is not a security issue. However, modern PCs and laptops have built-in audio hardware that can change the function of the output and input jacks within the software. 

Researchers from the University of the Negev’s Cyber Security Research Center found that malware can be used to turn an output jack into an input jack, turning a connected speaker into a microphone. Here is a video clip where they illustrate the attack.

As a result, they recommend that high-security facilities do not allow the use of speakers, headphones, or earphones to create an “audio gap separation.”

In less strict settings, microphones may be banned while speakers are allowed. However, since speakers can also function as microphones, only one-way speakers should be permitted, as they cannot be used as microphones.

Exploiting IoT and Smart Speakers:

Internet of Things (IoT) devices, including smart speakers like Amazon Echo or Google Home, are particularly vulnerable to eavesdropping attacks. These devices are always connected to the internet and usually feature built-in microphones for voice commands.

As such, attackers can potentially exploit security flaws in these devices or their supporting infrastructure to gain unauthorized access and enable covert audio recording.

Such attacks can be executed by exploiting vulnerabilities in the device’s firmware, its communication protocols, or the cloud services it relies upon.

Additionally, weak or compromised user credentials (such as email addresses and passwords) can also be used to gain unauthorized access to smart speakers and their linked accounts, providing an attacker with another avenue for potential eavesdropping.

Woman presenting data in a meeting. A man whose laptop is hacked, has his laptop's speaker listening and recording the meeting

Assessing the Risk: Is Your Speaker Vulnerable?

Not all speakers are equally vulnerable to hacking. The risk level depends on factors such as the device’s security features, how up-to-date its firmware is, and how the device is being used. Devices with weak security features or out-of-date firmware are more likely to be compromised.

However, it’s essential to understand that the likelihood of your speaker being targeted by hackers or eavesdroppers is relatively low. The average person is not likely to be the target of such attacks. Nonetheless, it’s crucial to be aware of the risks and take necessary precautions to secure your devices.

Keeping Your Bluetooth Speaker Secure

Here are some actionable steps you can take to minimize the risk of your Bluetooth speaker being turned into a listening device:

  • Update firmware regularly: Regularly check for and install firmware updates for your Bluetooth clients, that is, the PC and smartphones that connect to your speaker. These updates often include important security patches that can protect your device from known vulnerabilities.
  • Manage the visibility of your Bluetooth devices: When not in use, make your Bluetooth speaker undiscoverable to prevent unauthorized access. Additionally, only pair your speaker with devices you trust.
  • Turn off Bluetooth when not in use: As an added precaution, turn off the Bluetooth functionality on your speaker, your PC, and your smartphone when not in use. This can further reduce the chances of unauthorized access.

Final Thoughts

The thought of our speakers being used as potential listening devices is a chilling prospect. The technology that once provided us with entertainment and convenience can now be exploited for malicious purposes. 

As we have explored, the risks of our speakers being turned into listening devices are very real but not inevitable. It is crucial to be vigilant and take steps to keep your speaker secure, such as updating the firmware regularly, disabling the microphone when not in use, and using antivirus software on our PCs, laptops, and smartphones. 

It is up to us to stay informed and take proactive measures to protect ourselves and our privacy in this ever-connected world. As the old adage goes, “Better safe than sorry.”

Mike Chu

Mike is a web developer and content writer living as a digital nomad. With more than 20 years of devops experience, he brings his "programmer with people skills" approach to help explain technology to the average user. Check out his full author bio by clicking here.

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