U.S. Patent 7,437,290, filed in October 2004, describes a filter that would recognize undesirable spoken words and render them "unintelligible or inaudible."
Microsoft used the example of MMOs as a product that could benefit from such technology, but also said radio and TV broadcasts could take advantage of such an invention.
Microsoft would take particular interest in advancing a filter, as it has taken a proactive stance in voice communications in games for years with Xbox Live.
"Either other participants in the online game or spectators who are observing and/or listening to the participants' interaction should not be exposed to such undesired language," reads the patent.
Microsoft has yet to announce any product or service that employs such technology.
Thanks to Ars Technica.