In addition to vacuuming up troves of emails, web searches, and other written records, the United States' National Security Agency (NSA) had devised a way to collect spoken communication as well, according to documents from the leaked archive of NSA whistleblower Edward Snowden and reported on Tuesday by The Intercept.

In a top secret government document from 2006, NSA analysts discussed the development of what they called "Google for Voice," which automatically recognizes spoken content, such as in phone calls, "by creating rough transcripts and phonetic representations that can be easily searched and stored," Intercept journalist Dan Froomkin reports.

Further, a second document also from 2006 describes, as Froomkin writes, "extensive use of keyword searching as well as computer programs designed to analyze and 'extract' the content of voice conversations, and even use sophisticated algorithms to flag conversations of interest.

"Spying on international telephone calls has always been a staple of NSA surveillance, but the requirement that an actual person do the listening meant it was effectively limited to a tiny percentage of the total traffic," Froomkin reports. "By leveraging advances in automated speech recognition, the NSA has entered the era of bulk listening."

The reporting notes that these advances were made "with no apparent public oversight, hearings or legislative action." Further, the USA Freedom Act currently making its way through Congress doesn’t address the topic at all.

You can read the complete reporting on the NSA's speech-to-text capabilities at The Intercept.