Essentials of Static Noise
written by: Kelly

In the paranormal field great emphasis is placed on the collection of EVP’s (Electronic Voice Phenomena). This consists of the search (localized and/or archival) for audio communication of extraordinary, if not entirely unnatural, origin. In order to properly assess such data, any investigator requires a level understanding of the more significant audio events they are likely to encounter when searching for unusual recordings.

Many paranormal investigators utilize static and/or radio waves as a potential tool for communicating with an intelligent-type haunt, or at least in the hopes of collecting evidence of a residual-type event. Tools that are used for these experiments range from simple audio recording devices to much more sophisticated equipment, and the list even encompasses some custom receivers designed specifically for use with paranormal research. Key to understanding any data that can not be explained by noise pollution (unwanted environmental sound which is not always readily apparent to the observer due to it’s consistency within the environment, i.e. the hum of a generator or the muted sound of a radio playing in another room) is a foundational understanding of static noise. It is worth noting, however, that when subjected to a constant background of noise pollution, humans are capable of all but tuning out certain regularly repeating sounds. These can appear prominent later on in a recording, when the observer is no longer subjected to the original pollution and therefore is again sensitive to it’s presence.

In broadcasting and recording, audio noise (also known as static) is residual sound that is often is perceived as a hissing or humming in the absence of the intended signal, but can also be disruptive to another signal, with varying random frequency and signal strength. Static noise is classified in many different “colors” which refer analogously to the spectrum of light- for example, if the wave pattern for “white” noise were translated into a wave of light rather than sound, the pattern would result in white light. There are many classifications for static noise, and in the field of paranormal research some of the most prominent are White, Pink, Brown, Blue, Green, Red, and Gaussian.

White Noise is randomly generated and is often said to have a soothing effect on the human body because the main characteristic of this static is that it has a constant, equal intensity at any center frequency. This means that given a specific bandwidth (the range between the highest to lowest frequency found in the white noise signal) the static will in fact be equally intense whether it exists between 700-720Hz or between 50-70Hz. This does not mean, however, that the observer will perceive the signal as having equal strength since the human ear is bias to understanding lower frequencies as being also of lower intensity.

Pink Noise, however, is often used as a reference in audio craft because of it’s ability to balance the human ear’s perception and the intensity to appear equal and constant. The wave pattern of Pink noise decreases intensity proportionally as the frequency increases, and the ratio by which this occurs is roughly equal to that by which the human ear processes information. Because of this, the intensity is actually dropping as the frequency increases; yet a human observer will hear the intensity as remaining constant as the pitch changes.

Brown Noise, sometimes called Red Noise (which has several alternate classifications, and is only referred to as “Red” in order to keep consistent with the color classification) is actually similar to Pink Noise, but with a more drastic decrease in power density. Hence, this static will sound more intense at the lower end of the spectrum (and in fact, is), and will be perceived to (and in fact, does) decrease intensity as the frequency becomes higher.

Blue Noise operates opposite of Brown Noise, this static is perceived (and in fact does) increase in intensity as it increases in frequency, and vice versa. Along with Brown Noise, Blue Noise also only operates in a specific range of frequencies.

Green Noise is less scientifically notable, it derives from a collection of several long term analyses of outdoor sites. Green noise is considered the static noise of the outdoor world (an aggregate of distant, natural sounds), and actually seems to correlate closely with Pink Noise, but demonstrates a surge of intensity around 500Hz.

Another classification for Red Noise (separate from that listed about under Brown Noise) is also referred to as Oceanic Ambient Noise. This static is classified as red, because it represents noise pollution from distant sources, but whose whole wave pattern is not necessarily present since the Ocean has a tendency to absorb the waves of higher frequency. This effect occurs on or near bodies of water, and results in the observer only receiving the lower frequencies of the original bandwidth of the sound signal; in example, a sound which may have had many facets could be reduced to a low rumble by means of this process selectively eliminating the higher frequency components.

Lastly, Gaussian Static is notable chiefly because of the emphasis that the paranormal research field has come to place on electrical phenomena. This is the random static, similar to white noise, which results from the movement of electricity through a receiver. This is the static which is most readily recognizable, as it is the phenomenon which results in the static displayed by a television set when it is tuned to a channel that is not operating.

When assessing data that has an amalgamation of static or radio waves, or when assessing the credibility of receiving tools which are widely controversial in paranormal study, a foundational understanding of static noise is crucial to formulating an informed hypothesis.