Physics of Sound and Vibration: Effects On Human Electro-Dynamic Physiology

  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 pul

  Patent No. 4034741   Noise generator and transmitter (Adams, et al., Jul 12, 1977) Abstract An analgesic noise generator employs a circuit that can be switched to provide a variable waveform from an active noise source out of an integrated circuit amplifier.   Notes:   BACKGROUND In todays active, mobilized society noise has become a common problem. No where is this felt more than when one is trying to fall asleep. In an effort to aid in sleeping the use of sleeping tablets has mushroomed. As is well known, however, this approach to the problem often creates physical and psychological side effects. For this reason it was early on considered advantageous to induce sleep by physical methods. One such early method was to use electrodes to apply rectangular pulses. Another development was to create a hypnotic effect with lights, i.e., alternately dimming and brightening of a light source. Recently it has been rec