Low Frequency Hum in the Earth

Tinnitus is not a disease, but a condition that can result from a wide range of underlying causes: neurological damage (multiple sclerosis), ear infections, foreign objects in the ear, nasal allergies that prevent (or induce) fluid drain, or wax build-up. Withdrawal from benzodiazepines may cause tinnitus as well. In-ear headphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, are a common cause of tinnitus when volume is set beyond moderate levels.

Tinnitus may be an accompaniment of sensorineural hearing loss or congenital hearing loss, or it may be observed as a side effect of certain medications. However, the most common cause is noise-induced hearing loss.

As tinnitus is usually a subjective phenomenon, it is difficult to measure using objective tests, such as by comparison with noise of known frequency and intensity, as in an audiometric test. The condition is often rated clinically on a simple scale from "slight" to "catastrophic" according to the practical difficulties it imposes, such as interference with sleep, quiet activities, and normal daily activities.[1]

Tinnitus is common: about 20% of people between 55 and 65 years old report symptoms on a general health questionnaire, and 11.8% on more detailed tinnitus-specific questionnaires.[2]

Tinnitus can be perceived in one or both ears or in the head. It is usually described as a ringing noise, but in some patients, it takes the form of a high-pitched whining, electric buzzing, hissing, humming, tinging or whistling sound, or as ticking, clicking, roaring, "crickets" or "tree frogs" or "locusts (cicadas)", tunes, songs, beeping, sizzling, sounds that slightly resemble human voices or even a pure steady tone like that heard during a hearing test.[3] It has also been described as a "whooshing" sound, as of wind or waves.[4] Tinnitus can be intermittent, or it can be continuous, in which case it can be the cause of great distress. In some individuals, the intensity can be changed by shoulder, head, tongue, jaw, or eye movements.[5]

Most people with tinnitus have some degree of hearing loss,[6] in that they are often unable to hear clearly external sounds that occur within the same range of frequencies as their "phantom sounds".[7] This has led to the suggestion that one cause of tinnitus might be a homeostatic response of central dorsal cochlear nucleus auditory neurons that makes them hyperactive in compensation to auditory input loss.[8]

The sound perceived may range from a quiet background noise to one that can be heard even over loud external sounds. The term tinnitus usually refers to more severe cases. Heller and Bergman (1953) conducted a study of 100 tinnitus-free university students placed in an anechoic chamber and found 93% reported hearing a buzzing, pulsing or whistling sound. Cohort studies have demonstrated damage to hearing (among other health effects) from unnatural levels of noise exposure is very widespread in industrialized countries.[9]

For research purposes, the more elaborate Tinnitus Handicap Inventory (THI) is often used.[10] Persistent tinnitus may cause irritability, fatigue, and on occasions, clinical depression[11][12] and musical hallucinations.[13]

As with all diagnostics, other potential sources of the sounds normally associated with tinnitus should be ruled out. For instance, two recognized sources of very high pitched sounds might be electromagnetic fields common in modern wiring and various sound signal transmissions. A common and often misdiagnosed condition that mimics tinnitus is Radio Frequency (RF) hearing,[14] in which subjects have been tested and found to hear high-pitched transmission frequencies that sound similar to tinnitus.

if you can hear it
and the sound is external
then you should be able to measure it with appropriate low frequency microphones

a spectral analysis of the result would be a good starting point to identify its origin

... posters who attack anything that isn't sanctioned by the media approved view of reality.

This is not a fair characterization, to say the least. Some people, for some peculiar reason, really like to have some kind of credible evidence. Go figure. In this case direct personal observation leads me to believe that "something" is happening.

you can make an audio file on your computer...

then spectrum analyze it with freeware, like Audacity

only need to locate a microphone with low frequency response

it seems you are so focused on hearing the "sounds of nature" that you are missing the sounds of nature. Don't focus on your preconcieved notion of what nature sounds like. Try tuning into the sound, something may be revealed.

In this case direct personal observation leads me to believe that "something" is happening. But I'm not going to conclude that it's a secret government mind control program or a soviet plot left over from the cold war era. Again, go figure.

if you accept Tom Brown as the end all of nature awareness then I accept your statement.

Song of the Humpback Whale
Spectrogram of Humpback Whale vocalizations. Detail is shown for the first 24 seconds of the 37 second recording Humpback Whale "Song". The ethereal whale "songs" and echolocation "clicks" are visible as horizontal striations and vertical sweeps respectively. Spectrogram generated with Fatpigdog's PC based Real Time FFT Spectrum Analyzer.

Humpback Whale "Song"
Recording of Humpback Whales singing and Clicking.
Problems listening to this file? See media help.

Two groups of whales, the Humpback Whale and the subspecies of Blue Whale found in the Indian Ocean, are known to produce a series of repetitious sounds at varying frequencies. This is known as whale song. Marine biologist Philip Clapham describes the song as "probably the most complex in the animal kingdom".[13]

Male humpback whales perform these vocalizations only during the mating season, and so it is believed the purpose of songs is to aid sexual selection.[6] Whether the songs are a competitive behavior between males seeking the same mate, a means of defining territory or a "flirting" behavior from a male to a female is not known and the subject of ongoing research.[citation needed] Males have been observed singing while simultaneously acting as an "escort" whale in the immediate vicinity of a female. Singing has also been recorded in competitive groups of whales that are composed of one female and multiple males.[citation needed]

Interest in whale song was aroused by researchers Roger Payne and Scott McVay after the songs were brought to their attention by a Bermudian named Frank Watlington who was working for the US government at the SOFAR station listening for Russian submarines with underwater hydrophones off the coast of the island.[14]

The songs follow a distinct hierarchical structure. The base units of the song (sometimes loosely called the "notes") are single uninterrupted emissions of sound that last up to a few seconds. These sounds vary in frequency from 20 Hz to upward of 24 kHz (the typical human range of hearing is 20 Hz to 20 kHz). The units may be frequency modulated (i. e., the pitch of the sound may go up, down, or stay the same during the note) or amplitude modulated (get louder or quieter). However the adjustment of bandwidth on a spectrogram representation of the song reveals the essentially pulsed nature of the FM sounds.

A collection of four or six units is known as a sub-phrase, lasting perhaps ten seconds (see also phrase (music)).[citation needed] A collection of two sub-phrases is a phrase. A whale will typically repeat the same phrase over and over for two to four minutes. This is known as a theme. A collection of themes is known as a song.[citation needed] The whale will repeat the same song, which last up to 30 or so minutes, over and over again over the course of hours or even days.[citation needed] This "Russian doll" hierarchy of sounds has captured the imagination of scientists.[weasel words][citation needed]

All the whales in an area sing virtually the same song at any point in time and the song is constantly and slowly evolving over time.[citation needed] For example, over the course of a month a particular unit that started as an "upsweep" (increasing in frequency) might slowly flatten to become a constant note.[6] Another unit may get steadily louder. The pace of evolution of a whale's song also changes—some years the song may change quite rapidly, whereas in other years little variation may be recorded.[6]