Holosonic Sound Field
A holosonic sound field is like a hologram with sound. It is created by a highly sophisticated recording and playback system that operates similar to computed tomography(CT). It uses a series of speakers/microphones to make sounds appear to come from anywhere in a room.
A simple holosonic system could be created with as few as 8 speakers arranged in a cube pattern, but the resolution on such a system would be low and would barely work at just one point in a room. The CIA uses systems that create a holosonic field in an entire building and use thousands of speakers operated by a supercomputer, for MK-ULTRA style mind research.
CIA uses of holosonic sound fields
Simulated Auditory hallucinations
The CIA uses a holosonic system to generate noises coming from all over a room to try to make a subject believe that he or she is hallucinating. Sounds may be recorded that the subject hears for a few days before they enter the holosonic facility, and then replay the sounds back as if the person is remembering sounds and hearing them outside their head. They combine it with hallucinogenic drugs that are to LSD and sodium pentothal what advanced pharmaceuticals are to penicillin.
Rehearsed conversations are rehearsed and recorded by actors. Later the conversations are played back while the actors, in exactly the same positions, "lip synch" to the recorded audio. The audio can be manipulated before it is played back. For example: the volume of the audio can be raised and manipulated to enhance the words so they can be listened to more easily, and can help keep a subject awake(sleep deprivation tests in which a subject is drugged into being unable to sleep deeply make the person tend to be very sleepy while awake). Specific words can be enhanced and modified to be other words(to make a subject feel strange, they may make random words sound sexual: "...I have seen this when..." can be changed to "...I have PENIS when..." or "...are none that I know that can..." can be changed to "...are none DADDY NO that can..."(they like to find sexual perversions or sensitivities and use them to make the subject feel uncomfortable).
Along with the played back performance, and the drugs, strange occurrences or objects can be used to confuse a subject. For example, a woman may wear extremely exaggerated makeup, even to the point of having two eyebrows (which a highly drugged subject is unlikely to ask about, especially with all the other strange occurrences).
How the system works
The Speakers that the system uses are also used as the microphones. That way, when the audio that was recorded is played back exactly how it was recorded, the sounds will be recreated in the room, like a CT scanner recreates a 3D object. It can also be thought of as working as a "reverse CT" system.
What it is used for
One such facility is located in Wilford Hall Medical Center , at Lackland Air Force Base  in San Antonio, Texas. A fake "psychiatric unit" on the 4th floor called "4D" is used for MK-ULTRA style mind research. An other part of the hospital on the 1st floor that can create a holosonic field is converted to a fake "emergency room" where the subject is admitted to the "psychiatric unit".
Quotes from the actors of 4D
“This is because of sleep deprivation”