Patent No. 4034741 Noise generator and transmitter
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