摘要:
A active noise control system is described for attenuating an undesirable noise that containing multiple noise components having different frequencies. The system includes a configuration of signal generators and corresponding paired adaptive filters. Each signal generator produces a generator output signal containing one or more sinusoidal signal components, with each signal component having a frequency corresponding to a respective one of the noise frequency components. Separate signal generators are used to produce those sinusoidal components having frequencies corresponding to noise component that are adjacent with respect to their frequencies. Each adaptive filter operates on the generator output signal produced by its corresponding paired signal generator in accordance with its filtering characteristics to provide a respective filtered output signal. The filtered output signals from each adaptive filter are summed to obtain an output canceling signal, which drives an actuator to produce output canceling waves that are superpositioned with the undesirable noise. An error sensor measures the level of residual noise resulting from the superposition of the canceling waves and the undesirable noise, and provides an error signal for adapting the characteristics of the adaptive filters so as to minimize the level of residual noise.
摘要:
An electronic pillow including a pillow unit encasing at least one error microphone and at least one loudspeaker in electrical connection with a controller unit, the pillow unit also including a power source, and a reference sensing unit including at least one reference microphone in electrical connection with the controller unit, the controller unit including an algorithm for controlling interactions between the error microphone, loudspeaker, and reference microphone. A method of abating unwanted noise, by detecting an unwanted noise with a reference microphone, analyzing the unwanted noise, producing an anti-noise corresponding to the unwanted noise in a pillow, and abating the unwanted noise. Methods of hands-free communication, recording and monitoring sleep disorders, providing real-time response to emergencies, and playing audio sounds.
摘要:
A feedforward active noise control system (50) is provided for generating an anti-noise signal to attenuate a noise signal provided through a media. The feedforward active noise control system (50) performs on-line feedback path modeling and feedback path neutralization and includes a reference sensor (16), a secondary source (18), an error sensor (20), and an active noise control system controller (10). The reference sensor (16) receives the noise signal and a feedback signal (22) and generates a primary signal x(n). The secondary source (18) receives a secondary signal s(n) and generates a corresponding anti-noise signal. The error sensor (20) receives a residual signal and generates an error signal e(n) in response. The active noise control system controller (10) receives the primary signal x(n) and the error signal e(n) and generates the secondary signal y(n) while performing on-line feedback path modeling.
摘要:
An electronic pillow including a pillow unit encasing at least one error microphone and at least one loudspeaker in electrical connection with a controller unit, the pillow unit also including a power source, and a reference sensing unit including at least one reference microphone in electrical connection with the controller unit, the controller unit including an algorithm for controlling interactions between the error microphone, loudspeaker, and reference microphone. A method of abating unwanted noise, by detecting an unwanted noise with a reference microphone, analyzing the unwanted noise, producing an anti-noise corresponding to the unwanted noise in a pillow, and abating the unwanted noise. Methods of hands-free communication, recording and monitoring sleep disorders, providing real-time response to emergencies, and playing audio sounds.
摘要:
The system employing and the processing of, an indirectly sensed signal representative of a periodic noise acoustic wave into an input signal for a noise cancelling system where the indirectly sensed signal is converted into a pulse signal per period that carries fundamental and harmonic frequency information of the periodic noise. A tachometer type RPM signal is processed in a counter circuit controlled by a logic circuit to produce a signal of one pulse per revolution with a controlled duration, the pulse amplitude is adjusted, the pulses are low pass filtered and any D.C. is blocked from the noise cancelling system input.
摘要:
A digital hearing aid (10) is provided that includes a microphone (12), a control and modeling circuitry (18), and a receiver (20). The microphone (12) receives an input sound signal x(t) and generates a digital input signal x(n) in response. The control and modeling circuitry (18) filters and amplifies the digital input signal x(n) and performs feedback neutralization and feedback path modeling to generate a digital output signal y(n). The receiver (20) receives the digital output signal y(n) and generates an output sound signal y(t) in response.
摘要:
A feedforward active noise control system (50) is provided that includes a reference sensor (16), a secondary source (18), an error sensor (20), and an active noise control system controller (10) for generating an anti-noise signal to attenuate a noise signal provided through a media. The feedforward active noise control system (50) performs on-line feedback path modeling and on-line secondary path modeling.
摘要:
An off-line modeling system (50) is provided for modeling a feedback path by calculating filter taps. The off-line modeling system (50) includes a reference sensor (16), a secondary source (18), and an off-line modeling circuitry (10). The reference sensor (16) receives a noise signal and a feedback signal (22) and generates a primary signal x(n) in response. The secondary source (18) receives a modeling signal v(n) and provides the modeling signal v(n) to the feedback path. The off-line modeling circuitry (10) includes a signal discrimination circuitry (54), a modeling signal generator (64), a feedback path modeling adaptive filter (60), and associated adaptive algorithm (62) and a summing junction (58). The signal discrimination circuitry (54) receives the primary signal x(n) and generates a modified modeling signal v′(n). The modeling signal generator (64) generates the modeling signal v(n). The feedback path modeling adaptive filter (60) receives the modeling signal v(n) and uses adaptive algorithm (62) to process the modeling signal v(n). In doing this, adaptive algorithm (62) calculates the filter taps. The summing junction (58) subtracts the output signal from the modified modeling signal v′(n) to generate the modeling error signal which is used by the adaptive algorithm (62).
摘要:
An off-line modeling system (50) is provided for modeling a feedback path and a secondary path by calculating feedback neutralization filter taps and secondary path compensation filter taps. The off-line modeling system (50) includes a reference sensor (16), a secondary source (18), an error sensor (20), and an off-line modeling circuitry (10). The reference sensor (16) receives a noise signal and a feedback signal (22) and generates a primary signal x(n) in response. The secondary source (18) receives a modeling signal v(n) and provides the modeling signal v(n) to the feedback path and the secondary path. The error sensor (20) receives a residual signal generates an error signal e(n). The off-line modeling circuitry (10) receives the primary signal x(n) and the error signal e(n) and generates the modeling signal v(n) while modeling the feedback path and the secondary path.