Abstract:
An ANR circuit, possibly of a personal ANR device, monitors a sound level of environmental sounds detected by a microphone external to an earpiece in which the ANR circuit is providing feedback-based ANR, and increases or decreases the degree of feedback-based ANR provided in response to the external microphone detecting a higher or lower sound level, respectively. Increasing and decreasing the degree of feedback-based ANR provided may be carried out by changing a variable loop gain of the ANR circuit and/or a range of frequencies of environmental sounds attenuated by the feedback-based ANR. An ANR circuit, possibly of a personal ANR device, reduces the degree of feedforward-based ANR that it provides in response to receiving an indication of the operation of a manually-operable control. The reduction of degree of feedforward-based ANR may be effected by turning off or otherwise deactivating the provision of feedforward-based ANR, reducing a range of frequencies of environmental noise sounds attenuated by the feedforward-based ANR to provide less attenuation of sounds detected by a feedforward microphone that are in a range of frequencies deemed to be those of human speech, and/or creating a notch in the range of frequencies of environmental noise sounds attenuated by the feedforward-based ANR to provide less attenuation of sounds detected by the feedforward microphone that are in a range of frequencies deemed to be those of human speech.
Abstract:
The present invention relates generally to global noise or sound control and, more particularly, to the control of sound radiated from stationary induction apparatus such as power transformers (1) and shunt reactors by use of active enclosures and active panels (6). The purpose of the invention is to markedly reduce the radiation of sound from the machine to all observation points in the surrounding field with a very lightweight, compact, non-airtight structure (5, 6, 7, 8, 9, 10, 11) which does not impair maintenance or repair of the machine.
Abstract:
A method of calibrating an earphone may include: securing an ANC earphone to a calibration fixture, the calibration fixture including an ear model configured to support the ANC earphone, the ear model having an ear canal configured to anatomically resemble a human ear canal and a concha configured to anatomically resemble a human ear concha, the ear canal extending from the concha to an inner end of the ear canal; generating, with the ANC earphone, an audio signal based on a reference tone; determining a characteristic of the audio signal; comparing the characteristic of the audio signal to a previously determined reference characteristic; and adjusting a gain value of the ANC earphone based on the comparing. Additional methods and apparatus are also disclosed.
Abstract:
A method of calibrating an earphone may include: securing an ANC earphone to a calibration fixture, the calibration fixture including an ear model configured to support the ANC earphone, the ear model having an ear canal configured to anatomically resemble a human ear canal and a concha configured to anatomically resemble a human ear concha, the ear canal extending from the concha to an inner end of the ear canal; generating, with the ANC earphone, an audio signal based on a reference tone; determining a characteristic of the audio signal; comparing the characteristic of the audio signal to a previously determined reference characteristic; and adjusting a gain value of the ANC earphone based on the comparing. Additional methods and apparatus are also disclosed.
Abstract:
Some demonstrative embodiments include devices, systems and methods of noise control. For example, a noise control system may be configured to process one or more first noise inputs from one or more first acoustic sensors, the one or more first noise inputs representing external noise sensed at one or more respective noise sensing locations on an outer surface of a sheltering structure; to process one or more second noise inputs from one or more second acoustic sensors, the one or more second noise inputs representing residual noise at one or more respective residual noise sensing locations on an inner surface of the sheltering structure; to determine a noise control pattern based at least on the one or more first noise inputs and the one or more second noise inputs; and to generate one or more control signals to control acoustic signals generated by one or more acoustic transducers based on the noise control pattern.
Abstract:
A driver/microphone assembly is suggested, in which the microphone (2) is arranged centred with the motor (8, 9) of the driver (1 ) between the membrane (4) and the motor (8, 9). In order to provide coupling between the microphone (2) and the space on the other side of the membrane (4) an opening (13) is provided in the membrane (4), which is located above the microphone (2). The inventive overall assembly requires a reduced space. The contacting wires (12) of the microphone (2) are led to the rear side of the assembly through a borehole (14) in the driver's motor (8, 9). The invention can advantageously be used in active noise cancelling headsets.
Abstract:
Active-noise-reduction (ANR) headsets protect the hearing of their users from loud persistent noises, such as airplane engines and construction equipment. These headsets generally include ear speakers and special circuitry to cancel or suppress certain types of loud persistent noises. One problem the present inventor recognized with active headsets, particularly those manufactured in mass quantities, concerns the performance variations that stem from inevitable variations in the fit of their earcups against heads of their users. For example, in putting on and taking off these headsets, some users experience low-pitched noises. Accordingly, the inventor devised, among other things, headsets that include front-cavity vents for equalizing the pressure between a front cavity portion of an earcup and an ambient environment.
Abstract:
A device for the active acoustic attenuation of an acoustic signal propagated through a duct. The device includes at least one first sensor means (2) for sensing a first acoustic signal, an attenuation actuator means (6) outputting an active acoustic attenuation signal in response to a selected control signal, and electronic control means generating the active acoustic attenuation signal for the actuator means. The first sensor means (2) and the actuator means (6) are arranged entirely within the duct in facing positions at a selected distance from the body of the duct, the axis of symmetry of the radiation from the actuator means and the axis of symmetry of the first sensor means (2) are substantially parallel to the acoustic signal propagation direction in the duct, and the actuator means (6) are arranged before the first sensor means (2) in the acoustic signal propagation direction in the duct.
Abstract:
An active noise and vibration reduction system for canceling noise in aircraft or other passenger carrying transportation systems (10) which utilizes a series of seat mounted microphones (6) and trim mounted speakers (4) in conjunction with a digital controller (15) with a class-D stage power amplifier (5) and which is synched to the aircraft alternator (16).
Abstract:
A transducer arrangement for audio reproduction comprising: first and second transducer diaphragms (22, 24); first and second coils (40) coupled to said first and second diaphragms (22, 24) respectively; a common magnet structure having two gaps (38) at opposite ends, each gap (38) adapted to receive one of said first and second coils (40); and a housing defining a common chamber (74) enclosed by said first and second diaphragms.