The record was witnessed by two college music professors and an acoustician. The frequency output of his voice was measured using a low frequency microphone, precision sound analyzer and laptop for post analysis.
These notes are so low they can only be heard by elephants and are so low that even Storms himself cannot hear them. He says he can feel them, explaining,"I kind of hear them in my head as far as the sound my vocal chords are making but, as far as the frequencies, it's something more or less that I feel."
Elephants are fascinating creatures. Their eyes are about 3.8 cm (1.5 in.) in diameter, but their vision is only moderate. Elephants navigate primarily orienting with the trunk, as opposed to sight. There have been documented occurrences of elephant herds being led by a blind member. The complete lack of vision did not hinder the blind member’s ability to fulfill its leadership role.
Elephants have good hearing though and are able to detect sounds as low as 14 to 16 hz (human low range: 20 hz) and as high as 12,000 hz (human high range: 20,000). Elephants frequently use infrasonic sounds, which are sounds emitted below the human hearing range, in long—distance communication. Research has shown that elephants are capable of recognizing calls and voices of particular individuals from 1 to 1.5 km (0.6-0.9 mi.) away. Their ears are used to funnel in sound waves from the environment, contributing to its keen sense of hearing.
In general, animals with large heads and wide-set ears are better adapted for hearing lower frequency sounds because the larger skull encompasses longer ear canals, wider tympanic membranes and larger middle ears.
Elephants also have a keen sense of smell, detecting water sources up to 19.2 km (12 mi.) away. Their sense of smell is in constant use, with the trunks moving back and forth, detecting new scents and information. Once a scent is drawn in through thee nostrils, there is a series of seven olfactory turbinals, located in the nasal cavity. Turbinals are curls of bone that have millions of olfactory receptor cells associated with them.
If smelling does not provide enough information, elephants may collect the substance with the trunk. Then the chemical information is passed on to its Jacobson’s organ, a chemical—detection unit located in the soft tissue of the upper palate (roof of the mouth). The organ is attached to the oral/nasal cavities and primarily functions to detect the estrus (reproductive) status of a female. This behavior is known as the flehmen response and is characterized by the elephant curling its trunk into its mouth.
Elephants are very tactile in nature, using all parts of their body to interact with one another in all forms of behavior, including parental, playful, aggressive, defensive, exploratory, sexual, and anti-predator.
The trunk is one of the most tactile appendages elephants have. It is used to stroke, touch, explore, caress, or reassure in care—taking and may also be used to slap or block in defense or dominance situations. The trunk is so sensitive to touch that it is capable of perceiving pressure differences as light 0.25 mm (0.01 in.) in depth, which is equivalent to a light brush against the skin. The strength of an elephant’s trunk is capable of lifting weights in excess of 250 kg (550 lb.).
Elephant trunks have extensive sensory motor cells, called pacinian corpuscles, that enable them to have a strong sense of touch. The pacinian corpuscles are composed of concentric membranes of connective tissue, similar to the layers of an onion. Between each layer of connective tissue is a slimy gel. When a movement or vibration is detected, the pressure deforms the gel and connective tissue layers of the pacinian corpuscles. This stimulates nerve endings and sends a signal to the brain. Pacinian corpuscles are also found in the soles of elephant feet, assisting in the detection of seismic vibrations of the Earth.
Many animals including elephants survived the Asian tsunami in 2004. It is thought these animals had advanced warning to the tsunami due to their detection of seismic vibrations. The tsunami’s approaching vibrations were detected by the pacinian corpuscles in the elephant’s feet and alerted them to the approaching storm.
Speaking of low frequency sounds, communication with submarines is difficult because radio waves do not travel well through good electrical conductors like salt water. The obvious solution is to surface and raise an antenna above the sea level, then use ordinary radio transmissions. However, a submarine is most vulnerable when on the surface. Early submarines mostly traveled on the surface, diving mainly to evade immediate threats because of their limited underwater speed and endurance.
During the Cold War, however, nuclear-powered submarines were developed that could stay submerged for months. To communicate with submerged submarines several techniques are used. Q and A about life on a submarine (U.S. Navy) Global Security's article on submarine communications simply explained.
Here is a LINK to a fascinating site describing the world of sound, including communicating underwater.
Deep secret – secure submarine communication on a quantum level