Patent No. 4191175 Method and apparatus for repetitively producing a noise-like audible signal

 

Patent No. 4191175  Method and apparatus for repetitively producing a noise-like audible signal (Nagle, Mar 4, 1980)

Abstract

A digital pulse generator and shift register repetitively produce bursts of digital pulses at a first adjustable repetition frequency. The repetition frequency of the pulses in each burst is also adjustable. A pink noise filter accentuates the lower burst frequency components near 7 hz and substantially attenuates all frequency components of the bursts above a first cut-off point near 10 Khz. A tunable band pass amplifier having a center frequency adjustable over a preselected range of frequencies optimally detectable by the average human ear accentuates the pink noise filter output near 2.6 Khz. The tunable amplifier drives an audible signal source with noise-like pulses of varying amplitudes and frequency components. A low pass amplifier may be connected to the pink noise filter to generate a train of pulses having a repetition frequency near 7 hz which pulses a light source in synchronism with the audible noise-like signal.

 

Notes:

BACKGROUND OF THE INVENTION

The present invention is directed to a method and apparatus for producing a noise-like signal for inducing a hypnotic or anesthetic effect in a human being. The invention also has application in crowd control consciousness level training (biofeedback) and heart rate detection training (biofeedback). The invention may also be used in creating special musical effects.

The invention is particularly directed to the creation of a filtered repetitive noise-like signal alone or in combination with a repetitive visible signal. The audible signal has a pronounced effect on the human central nervous system.

Devices are known in the prior art for producing audible signals alone or in combination with a visible signal for inducing sleep. For example, see U.S. Pat. No. 3,576,185 to Shulz et al. which discloses a device for generating an audible pulsating sinusoidal signal and a visible signal in synchronism. Other devices which employ white noise sources for inducing sleep are also known. For example, see U.S. Pat. No. 3,835,833 to Limoge. Still other devices are known wherein sleep is induced by pulsing a light source at relatively low frequencies. See U.S. Pat. No. 3,388,699 to Webb et al. It is also known that the nervous system can be stimulated by amplitude modulated audible carrier signals at the alpha and theta frequencies of the brain. See U.S. Pat. No. 3,753,433 to Bakerich et al. (electroencephalophone feedback system).

None of these devices employ filtered repetitive noise-like audible signals to influence the human central nervous system. Such signals, however, are remarkably effective in changing states of consciousness or inducing hypnotic, anesthetic or sleep-like states.

An advantage of the invention is that it provides a filtered repetitive noise-like audible signal extremely effective in influencing the human central nervous system.

A further advantage of the invention is that it is versatile in that the audible signal frequencies can be adjusted to match the sensitivity of the central nervous systems of different individuals.

A further advantage of the invention is that it is of simple design and construction and relatively easy to trouble shoot and repair.

Other advantages appear hereinafter.

BRIEF SUMMARY OF THE INVENTION

Method and apparatus for repetitively producing a noise-like audible signal. Bursts of digital pulses are repetitively generated at a first frequency. The repetition frequency of the digital pulses within each burst is much higher than the burst frequency. The lower frequencies of the bursts near 7 hz are accentuated and the frequencies which lie above a first cut-off point are substantially attenuated by a pink noise filter. The frequencies of the bursts in an adjustable band pass preferably centered near 2.6 Khz are then accentuated by a tunable band pass amplifier. The output of the tunable band pass amplifier is a repetitive noise-like signal which drives an audible signal source. The 7 hz frequency component of the pulse bursts at the pink noise filter out-put may be further accentuated by a low pass amplifier which drives a light source.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.