It used to be that it might only be dogs that could hear high-pitched frequencies that human beings couldn’t. Now it appears that our iPhones might be gaining that capacity.

Zack Whittaker for Zero Day has just written about emerging technology that allows applications to use ad-tracking audio signals that can be picked up by phones but not by their owners (“Hundreds of privacy-invading apps are using ultrasonic sounds to track you”;http://www.zdnet.com/article/hundreds-of-apps-are-using-ultrasonic-sounds-to-track-your-ad-habits/?loc=newsletter_large_thumb_featured&ftag=TRE17cfd61&bhid=24712762005371291890829436782174).

How is this possible? As Mr. Whittaker writes, the ultrasonic cross-device tracking can be done via high-frequency tones in ads, billboards, web pages and even from brick-and-mortar stores as well as sports arenas.

While this technology is still evolving, it’s gaining in popularity. What’s the potential danger? Again, Mr. Whittaker notes that using the phone’s microphone, information about where the owner’s been, what she’s seen and maybe even the websites she’s visited can be collected to create a profile.

What can ┬ábe done to prevent this? While the technology’s still new, Mr. Whittaker provides an important, very useful tip: if an application asks for the phone’s microphone, and if the microphone’s not needed to use the application then don’t permit this! Instead, just turn off the microphone.

His article contains more details about this latest privacy threat. I urge people to read it to gain more understanding about this latest privacy threat.