The US Patent Office published a new patent this week that reveals US government plans to license and sell hearing aid devices and other hearing aid equipment to third parties.

The filing, which was filed in February, covers “the use of a microphone, loudspeaker, or other sound-emitting device for the purpose of listening to a voice-controlled communication, or to a conversation between two persons who have a mutual understanding of the message.”

The patent was revealed in a lawsuit filed by the Electronic Frontier Foundation (EFF) in 2015, and it was filed by US Department of Justice and Department of Defense (DoD).

The DoD filed its own lawsuit against the DOJ, accusing the DoD of violating a court order preventing the DoDs use of foreign military equipment for intelligence gathering.

The patent covers “an apparatus and method for generating sound signals for use in an audio communications system.”

According to the filing, the apparatus and methods include: “a microphone that is configured to emit a signal when the microphone is activated; a microphone system that is connected to a microphone device for transmitting the voice signal, or an audio device for receiving the voice signals from a microphone; and an audio interface that is provided for connecting the microphone device to the microphone system, for communicating with the microphone via a communication channel, and for displaying the voice-generated audio signal in a video mode.”

The filing does not say how much the patent covers, or whether any specific product will be developed.

According to EFF, the US government is trying to sell the hearing aid device to foreign companies that use the same equipment to communicate with drones and other aircraft.

“The US government must be transparent about how it plans to make the devices in use in the United States, so the public has a clear understanding of what the government is actually selling, and why,” EFF said in a statement.

“If the government has an official plan to sell military-grade hearing aids to foreign governments, the public should be able to see it in action.”

In its suit, EFF accused the DoE of selling the technology to the Chinese military, which is believed to be building the drones.

“To avoid confusion, the DoEs official sales strategy does not specify whether the equipment will be used for the use of surveillance or intelligence gathering,” the filing reads.

“Instead, the official plan indicates that the government will use the equipment for military purposes and will not disclose any specific details regarding the use or the capabilities of the equipment, such as what it will be for.”

According the filing and a statement from EFF, “The US military has long had a history of selling equipment to repressive regimes, including the Chinese government, which has also been using military-type hearing aids for years to help control the voices of its citizens.”