Google, Inc. on Tuesday was granted a patent for a voice interface for search engines.

The patent document suggests that Google will be leveraging its logs of stored text and audio queries to improve speech recognition and relevancy, as the company does currently with text keywords. It says, “The query logs may consist of audio data (i.e., a recorded query) and/or a textual transcription of the audio data…. The query logs may also consist of typed query logs from, for example, a text-based search engine.”

The existence of audio query logs will likely prove as tempting to the Department of Justice and other entities as text search data. But audio queries are likely to contain even more information than text queries in the form of background noise. Anything said in the area of someone speaking into his or her phone could potentially be recorded and stored with GPS coordinates and a time stamp.