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Effects of Infrasound on the Ears

A dog whistle produces a high-pitched frequency that can only be heard by an animal ear. This frequency is known as infrasound, and may or may not have an effect on the human ear at certain levels. Infrasound ranges from 15 to 20 herz: too low to be heard by humans. Depending the frequency's pitch, infrasound can cause fear, have a negative effect on a person physically and even cause death.

  1. Types of Infrasound

    • Infrasound occurs both naturally and in man-made forms. Man-made sounds typically stem from machines specifically developed to produce the sound for various reasons. Some machines not intended for that purpose also create infrasound frequencies that may affect the ear. For example, wind turbines, engines, airplanes, cars, buses and trains all produce infrasound.

      Natural infrasounds are produced by both animals and earthly elements. Natural disasters like volcanic eruptions, tsunamis and earthquakes can all emit infrasound frequencies, as can tidal waves, the calving of glacial ice, waterfalls and the common thunderstorm.

    Physical Effects of Infrasound

    • When exposed to infrasound, the human ear feels the vibration from the frequency, which is under the standard 20,000 hertz needed to be heard by humans. But the vibration causes stimulation in the outer hair cells of the cochlea within the ear.

      Prolonged exposure to high frequency infrasound can create a disruption in the normal functions of the middle and inner ear. This disruption can lead to nausea, impaired equilibrium and disorientation. Mild doses can lead to illness but intense infrasound exposure can lead to death.

      On the other hand, some low frequency infrasounds may cause a euphoric state. Mild exposure can elevate the heart rate and blood pressure, causing a release of endorphins which lead to an adrenaline response.

    Psychological Effects of Infrasound

    • In addition to the physical effects from infrasound exposure, there is a psychological effect.

      According to a 2002 study, "Soundless Music" which introduces a man-made form of infrasound to people attending a concert, people surveyed said they had various emotional and physical experiences during the show. Some audience members said they experienced feelings of anxiety, coldness and tingling sensations. Some even said they felt uncomfortable and that they felt deeper sensations of emotions.

      Infrasound has also been contributed to reports of ghost sightings, feelings of spiritual empowerment or the holy ghost.

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