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Method and apparatus for suppressing narrow-band noise in passenger cabin of vehicle Apparatus for suppressing noise in the passenger cabin of a vehicle has at least one converter, a programmable computer and at least one acoustic sensor. The computer is configured to apply the electroacoustic model of the passenger cabin to the model of an adjustment system, having a fixed coefficient master controller which is connected to a variable coefficient unit, having a Yule parameter in form of a Yule Q unit. In the method, the first step involves determining and calculating the electroacoustic model and control law for at least one predetermined noise frequency. At the second step, the computer applies the control law to the electroacoustic model in real time in accordance with the current noise frequency to be suppressed. |
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Acoustic noise generator includes a control unit, a display unit, an inspection unit, a power supply and battery charge unit, a battery, a low-frequency signal generator and rotation actuating unit, wherein the low-frequency signal generator is in form of a cylindrical housing, on the inner surface of which there are uniform protrusions; a rod is placed in the housing in line with the axis of the housing, with the possibility of rotation, where the same ends of bearing elements are rigidly attached, and the other ends are fitted with first contact elements with the possibility of translational displacement thereof along the bearing elements and with the possibility of interaction with protrusions of the housing; on the outer surface of the housing there are uniformly arranged second contact elements, with the possibility of interaction thereof with the housing, wherein the rod of the low-frequency signal generator is kinematically connected to the rotation actuating element. |
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Device for noise compensation in car Device for noise compensation in a car with a receiver (10) which detects occurring noise, having a signal generator (8) which generates, based on the detected noise, at least one signal, and with at least one speaker (7) which generates, based on the signal, damping sound waves which are phase shifted with respect to the sound waves of the occurring noise, and emits said waves inside the car. The at least one speaker (7) is installed inside the car such that damping sound waves are emitted into the zone of the sleeping berth (11). |
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Aircraft with better acoustic comfort Aircraft comprises cabin. Said cabin comprises lining panels and system of active ambient noise control. Every lining panel is either active or passive panel. Active panel comprises drives supplied from aforesaid system. Panel of one type is mechanical interchangeable with that of the other type. Active panel supply wiring allows connection to active panels. Active panel supply system is connected to active panel supply wiring. Proposed method consists in that passive panel is replaced by active panel. The latter is connected to wiring of active sound control system, or active lining panel is disconnected from said system and replaced by passive panel. |
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System of active noise damping and its application Here is disclosed system (10) of active noise damping for active reduction of intensity of primary sound waves (16) containing control device (11), sensor (12) of error, reference sensor (13) and several exciters (14) of secondary sound waves. Exciters (14) of secondary sound waves are designed to emit waves (15) of noise damping. Also, control device (11) connected to secondary exciters (15) processes error signal (F) and reference signal ® and generates secondary signal (S) transmitted to secondary exciters (14) through corresponding communication lines to control their emission. Thus, secondary exciters (14) emit waves (15) of noise damping, which decrease error signal (F) and facilitate optimal attenuation of sound waves. Secondary exciters (14) are positioned at boundary of open passage (21) letting primary sound waves (16) to ensure active attenuation of sound waves in open space in the direction of their transmission behind open passage (21) by means of waves of noise damping operating as "acoustic screen". |
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Method for active suppression of acoustic noise Invention is related to facilities for protection against acoustic noise caused by operating ventilation systems in residential premises and in moving objects. Method includes excitation of additional noise fields, in which signals for excitation of additional fields with the help of negative feedback chain with application of acoustic field exciter, acoustic pressure receiver, chain of preliminary amplifier control and generator of control voltage. Besides preliminary amplifier amplification ratio is varied by supply of additional pressure receiver signal to control voltage generator input, with time of main pressure output signal advance, which satisfies the following condition: TAD≥3τc, TAD=L/c, where: TAD - value of output signal advance, τc - time constant of preliminary amplifier control circuit. |
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Device to attenuate vent system noise Invention relates noise protection devices. Proposed active-protection noise device comprises pressure receiver 2, preamplifier 3 with controlled transmission ratio, compensator 4, inverting amplifier 5, radiator, auxiliary pressure receiver 7 and control voltage shaper 8. Auxiliary pressure receiver is arranged shifted relative to the primary one, the shift magnitude from the formula TAD≥3τs, TAD=L/s, where TAD is the output signal advance magnitude, τs is the preamplifier control circuit time constant, L is the shift of auxiliary pressure receiver relative to the main one, s is sound velocity in air. |
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Invention relates to protective devices for ears. The ear protectors have a headset for passive sound absorption, a microphone placed outside the ear protectors, a loud speaker placed inside the headset, and an amplifier for amplifying acoustic signals picked up by the microphone and transmitting signals to the loud speaker. The microphone, amplifier and loud speaker are combined into a device, to be placed into a depression made in the headset. The said depression has a lower wall, which forms a partition wall between the depression and the inner side of the headset. The lower wall has a perforation or opening for the loud speaker, facing inside the headset. |
Another patent 2513044.