Subliminal Acoustic Manipulation uses sound at frequencies or volumes which are below the threshold of conscious hearing that influence the nervous system of a person’s, mood, or behavior without him being consciously aware of it. There is also a US patent “US6017302A” for subliminal acoustic manipulation of nervous systems.

The US’302 patent discloses details of a technique and apparatus for influencing human physiological and sensory reactions by generating subliminal acoustic pulses through low-frequency sound pulses.  It talks about the many physical and psychological impacts, that might result from specific frequencies, particularly those between 1/2 Hz and 2.5 Hz, having an impact on the brain and nervous system.

Subliminal Acoustic Pulses

Lower frequency sound waves ranging below 20 hz can have an impact on human behavior and body functions when it is tuned to some resonance frequencies.

Sensory Resonances

The frequency ½ and 2.5 Hz could induce feeling of relaxation, fatigue and reduction in brain activity with matching the frequency used.

This device is operated on battery which produces low frequency sounds. Its apparatus includes a Venting acoustic monopole which produces sounds by taking in and releasing air at a sub-audio frequency level.

The patent discloses some advantages of using subliminal Acoustic Manipulation of the Nervous System such as an aid to relaxation, sleep, or sexual arousal, and clinically for the control and perhaps treatment of insomnia, tremors, epileptic seizures, and anxiety disorders. There is further application as a nonlethal weapon that can be used in law enforcement standoff situations, for causing drowsiness and disorientation in targeted subjects.

The technology can be weaponized (Non-Lethal)

Long-Range Manipulation allows nervous system manipulation by adding weak subliminal acoustic pulses at person’s ears. Frequencies between 1/2 Hz - 2.5 Hz can be targeted in order to get the desired physiological and psychological impacts.

Weaponized Use in Law Enforcement or Military Contexts allows to utilize subliminal sound pulses to affect someone's behavior or mental condition during a standoff or hostage negotiation.

Potential Side effects

There may be a short term or long term chronic effect with this type of stimulation on the brain or mental state. 

With Lack of Control while using the device it might be challenging to control or undo the effects, as subject person may not get a rough idea about what is happening with them.

The technology has both useful and harmful applications. Technology itself is neutral it is neither good nor bad. It is our intention, awareness, and responsibility that determine whether it becomes a force for good cause or a source of distraction.