Abstract: In an active noise reducing headphone, a signal processor applies filters and control gains of both the feed-forward and feedback active noise cancellation signal paths. The signal processor is configured to apply first feed-forward filters to the feed-forward signal path and apply first feedback filters to the feedback signal path during a first operating mode providing effective cancellation of ambient sound, and to apply second feed-forward filters to the feed-forward signal path during a second operating mode providing active hear-through of ambient sounds with ambient naturalness.

Abstract: An active noise reducing headphone has an active noise-cancelling mode and an active hear-through mode, and changes between the noise-cancelling mode and the hear-through mode based on detection of a user touching a housing of the headphone or based on a command signal received from an external device. In another aspect, a signal processor in the headphone is configured to change between the active noise-cancelling and active hear-through modes based on a comparison of signals from a feed-forward microphone and a feedback microphone. During the hear-through mode, the signal processor detects high-frequency signals in the feed-forward path exceeding a threshold level indicative of abnormally high acoustic coupling of the output transducer to the feed-forward microphone, and applies a compressing limiter to the feed-forward path until the high-frequency signals are no longer detected at levels above the threshold.

Abstract: In an active noise reducing headphone, a signal processor is configured to apply first feedback filters to the feedback signal path, causing the feedback signal path to operate at a first gain level, as a function of frequency, during a first operating mode, and apply second feedback filters to the feedback signal path, causing the feedback signal path to operate at a second gain level less than the first gain level at some frequencies during a second operating mode. The first gain level is a level of gain that results in effective cancellation of sounds transmitted through or around the ear cup and through the user's head, and the second level is a level of gain that is matched to the level of sound of a typical wearer's voice transmitted through the wearer's head when wearing the headphone.

Abstract: A system for providing binaural telepresence includes two communication devices, and two sets of active noise reducing headphones having an active noise-cancelling mode and an active hear-through mode, coupled to the respective communication devices and configured to provide left and right feed-forward microphone signals to the communication devices. The first communication device is configured to transmit the first left and right feed-forward microphone signals to the second communication device. The second communication device is configured to provide the first left and right feed-forward microphone signals to the second set of headphones.

Abstract: In an active noise reducing headphone, a signal processor applies filters and control gains of both the feed-forward and feedback active noise cancellation signal paths. The signal processor is configured to apply first feed-forward filters to the feed-forward signal path and apply first feedback filters to the feedback signal path during a first operating mode providing effective cancellation of ambient sound, and to apply second feed-forward filters to the feed-forward signal path during a second operating mode providing active hear-through of ambient sounds with ambient naturalness.

Abstract: In an active noise reducing headphone, a signal processor applies filters and control gains of feed-forward and feedback active noise cancellation signal paths. The signal processor is configured to apply first feed-forward filters to the feed-forward signal path and apply first feedback filters to the feedback signal path during a first operating mode providing effective cancellation of ambient sound, apply second feed-forward filters to the feed-forward signal path during a second operating mode providing active hear-through of ambient sounds with ambient naturalness, and provide an input electronic audio signal to an output transducer via an audio playback signal path during both the first and second operating modes.

Abstract: Displacement of a moving diaphragm in an electroacoustic transducer is measured by modulating an electrical signal based on changes in capacitance between the voice coil assembly and the magnetic structure resulting from relative motion between the voice coil and the magnetic structure. The modulated electrical signal is demodulated to produce an output signal having a value proportional to the displacement.

Abstract: Apparatus and method for determining an operating state of an earpiece of a personal acoustic device and/or the entirety of the personal acoustic device through tests to determine the current operating state, wherein the tests differ depending on a current power mode of the personal acoustic device, and wherein at least one lower power test is employed during at least one lower power mode.

Abstract: An active noise reduction (ANR) circuit includes a digital feed-forward ANR pathway coupled to a feed-forward microphone, to detect environmental sounds in an environment external to a casing, and to a first acoustic driver to output sounds within the casing. The digital feed-forward ANR pathway applies a plurality of filters using a first set of coefficients to convert signals from the feed-forward microphone to feed-forward anti-noise sounds to reduce environmental sounds within the casing. In response to a stimulus, the digital feed-forward ANR pathway applies the plurality of filters using a second set of coefficients, which reduce the degree of feed-forward ANR to enable human speech sounds in the environment external to the casing to be conveyed from the feed-forward microphone to the acoustic driver with less reduction than provided by the first plurality of filters.

Abstract: An in-ear audio device has a casing on which is disposed one or more bags are positioned to be filled with fillable material during a customization process in which a test sound is acoustically output into an ear canal by an acoustic driver of the in-ear audio device while the one or more bags are being filled, and a microphone acoustically coupled to the ear canal is employed to detect sounds within the ear canal that are indicative of the frequency response of the acoustic output of the acoustic driver to determine when the degree of sealing of the ear canal by the one or more bags is sufficient to achieve a desired quality of frequency response.

Abstract: Apparatus and method of controlling provision of ANR, possibly of a personal ANR device, in which amplitudes of a piece of audio employed in the provision of ANR are monitored, and the compression of one or both of feedback and feedforward ANR reference sounds is made dependent on frequency such that a first sound of one frequency need only reach a lower amplitude to trigger compression, while a second sound of another frequency must reach a higher amplitude to trigger compression.

Abstract: A method for adjusting the performance of an electroacoustic transducer includes receiving, by gain adjustment circuit, a displacement signal corresponding to a relative motion between a magnetic structure of the electroacoustic transducer and a voice coil of the electroacoustic transducer. The method includes detecting, by the gain adjustment circuit, a displacement signal value of the displacement signal as one of meeting or exceeding a displacement signal threshold. The method includes modifying, by the gain adjustment circuit, a loop gain of an active noise reduction loop associated with the electroacoustic transducer when the displacement signal value of the displacement signal one of meets or exceeds the displacement signal threshold.

Abstract: Apparatus and method of reducing the provision of ANR at an one end of a range of frequencies at which the ANR is provided without reducing the provision of the ANR at the other end of the range of frequencies by repeatedly reconfiguring coefficients of one or more digital filters to reduce the provision of ANR at the one end in increments at a first recurring interval, and then later reversing the reduction in the provision of the ANR at the one end by repeatedly reconfiguring coefficients of the one or more digital filters in increments at a second recurring interval.

Abstract: In an ANR circuit of a personal ANR device, a digital filter is structured to introduce one or more zeros to add gain to introduce positive phase in the provision of feedback-based ANR, wherein the gain follows a frequency-dependent “ski-slope” gain curve with little gain added at lower audible frequencies, with increasing gain that increases with frequency added at higher audible frequencies, and with the increasing gain flattening at frequencies above audible frequencies.

Abstract: Displacement of a moving diaphragm in an electroacoustic transducer is measured by modulating an electrical signal based on changes in capacitance between the voice coil assembly and the magnetic structure resulting from relative motion between the voice coil and the magnetic structure. The modulated electrical signal is demodulated to produce an output signal having a value proportional to the displacement.

Abstract: In a personal ANR device having a pair of earpieces, each having a feedforward microphone and an ANR circuit associated therewith, each ANR circuit provides digital data representing environmental noise sounds detected by each ANR circuit's associated feedforward microphone. Such digital data may represent the environmental noise sounds as detected with little or not modification, or such digital data may be modified to some degree within each ANR circuit, perhaps to limit the range of frequencies that such digital data represents, before being provided to the other ANR circuit.

Abstract: A apparatus and method for determining an operating state of an earpiece of a personal acoustic device and/or the entirety of the personal acoustic device by analyzing signals output by at least an inner microphone disposed within a cavity of a casing of the earpiece and an outer microphone disposed on the personal acoustic device in a manner acoustically coupling it to the environment outside the casing of the earpiece.

Abstract: A noise reduction headset including a negative feedback active noise reduction signal processing path for providing active noise reduction, an electronic communication signal processing path, a talk-through signal processing path for providing talk-through capability, comprising at least one talk-through microphone separate from the electronic communication signal processing path, and a switching element for disabling one or both of the noise reduction signal path and the talk-through signal path.

Abstract: An ANR circuit, possibly of a personal ANR device, incorporates an signal processing topology to support the provision of feedback-based ANR, feedforward-based ANR and pass-through audio in which the topology incorporates a branch in which feedback anti-noise sounds are generated from feedback reference sounds received from a feedback microphone, a branch in which feedforward anti-noise sounds are generated from feedforward reference sounds, and a branch in which modified pass-through audio sounds are generated from pass-through audio sounds received from an audio source, wherein these three branches are combined to combine the generated sounds of each branch into a single output by which an acoustic driver, possibly of the personal ANR device, is driven.