Is It Possible for Someone to Transmit Their Voice or Audio to Your TV?

Yes, it is possible for someone to transmit their voice or other audio to your TV, allowing you to hear it in the background or over the main audio of what you're watching. This can be achieved in several ways, some more recent and some dating back to earlier technology. Understanding how it happens can help you take necessary precautions to secure your home and entertainment systems.

Smart TVs with Voice Assistants

Many modern smart TVs come equipped with voice assistants like Amazon Alexa, Google Assistant, or Apple’s Siri. These assistants can be activated remotely, providing a convenient way to control your device. However, if someone has access to your smart home network or the TVs voice assistant, they could potentially send audio to your TV. This could be done through mobile applications or by using the integrated voice assistant itself.

Screen Mirroring or Casting

Devices that support screen mirroring like Chromecast or Apple AirPlay can allow someone to cast audio directly to your TV. If they are within the same network, they can stream audio content, including their voice, over whatever you're watching. This is a common method used in home entertainment systems where multiple users share a network.

Audio Over Bluetooth

If your TV has Bluetooth capability, someone could pair their device with your TV and stream audio directly. This could include their voice or other sounds. Bluetooth is a wireless technology that enables short-range communication between devices, making it a convenient way to stream audio. However, it does require that the devices be paired and connected, which could present risks if unauthorized devices are used.

Wireless Microphones

Some devices can connect to your TV or audio system and allow for voice transmission. This could include wireless microphones that are designed to capture and transmit audio to your entertainment system. If someone has set this up in your home, they could potentially broadcast their voice or other sounds, which could be heard on your TV.

Malicious Software

In some cases, a smart TV can be compromised with malicious software. This software could be used to transmit audio without your consent. This is more common in devices with outdated software or poor security measures. While rare, it highlights the importance of keeping your devices updated and secure.

A Personal Incident

One person experienced a similar situation years ago. They heard voices coming from their old projection TV, which was 16 years old at the time. The TV was off, yet the voices were still present. This led them to assume it might have been a taxi CB radio. However, as we'll explore, there may be other explanations.

Early Technologies

Some of the early “baby monitors” worked by injecting signals into the AC lines within a house, modulating TV audio so that loud crying would break into the middle of your favorite show. However, these systems were not compliant with FCC regulations, leading to unwanted interference and even resonance in other devices.

Historical Instances

The problem of such systems was that they were not FCC-compliant and often shared transformer windings and ground circuits. This meant that interference could easily spread to other devices. A notable instance occurred in the NIST main auditorium, where a baby monitor caused interference during a classified technology conference. The sound of an unhappy infant broke into a discourse on high-power laser developments, which was both startling and disruptive.

The Fix

To resolve the issue, the system was redesigned to use fiber optics for connecting the audio system and power isolation techniques to prevent interference.

These experiences illustrate the importance of understanding the potential security risks associated with audio transmission to your TV and taking proactive measures to protect your home entertainment system. Regularly updating your devices, using strong passwords, and being aware of your home network’s security are all crucial steps in preventing unauthorized audio transmission.