Some Video Calling Apps Can Access Audio Even When Muted: Report

The issue of privacy almost always comes up when we discuss video calling apps. A new report sheds light on how some communication apps can continue to access user data even if the microphone is on mute.

The revelations come as part of a University of Wisconsin-Madison pre-print study. Researchers conducted tests for the study across a variety of video calling apps. Their findings reveal that several apps continue to access the microphone even after the user has hit the mute button. Among these are apps like Zoom, Discord, Google Meet, Slack, etc.

Researchers Kassem Fawaz and Yucheng Yang played a big role in the investigations. The two will present the findings of their report at the Privacy Enhancing Symposium in July.

“They found that all of the apps they tested occasionally gather raw audio data while mute is activated, with one popular app gathering information and delivering data to its server at the same rate regardless of whether the microphone is muted or not,” an excerpt from the researchers’ summary reads.

Researchers analyzed the muting mechanisms of 223 video conferencing apps

Fawaz said the idea to take a deep dive into videoconferencing apps’ behavior came after his brother realized that the microphone light remained on even after muting the mic. Fawaz then took the idea to Yang and came up with a plan. Researchers at Chicago’s Loyola University also contributed to the study.

The researchers analyzed 223 video conferencing apps to understand the behavior of their built-in muting mechanisms. They later came up with custom algorithms to ascertain whether they can parse the audio for activities such as cleaning, cooking, etc. The team found that they could predict the activity based on the audio data with 82% accuracy.

“When you’re cooking, the acoustic signature is different from someone who is driving or watching a video. So these types of activities can be distinguished just based on this acoustic fingerprint that was actually sent out to the cloud,” Fawaz said (via Input Mag). You can find the abstract of the report here.

Considering the notorious history of unauthorized data use by corporations, these findings hardly come as a surprise. Zoom and other apps named in the report are yet to explain the report’s findings. But since the researchers’ report isn’t official yet, we may have to wait a while.