Abstract: Embodiments of the invention may be used to implement a rate converter that includes: 6 channels in forward (audio) path, each channel having a 24-bit signal path per channel, an End-to-end SNR of 110 dB, all within the 20 Hz to 20 KHz bandwidth. Embodiment may also be used to implement a rate converter having: 2 channels in a reverse path, such as for voice signals, 16-bit signal path per channel, an End-to-end SNR of 93 dB, all within 20 Hz to 20 KHz bandwidth. The rate converter may include sample rates such as 8, 11.025, 12, 16, 22.05, 24, 32 44.1, 48, and 96 KHz. Further, rate converters according to embodiments may include a gated clock in low-power mode to conserve power.

Abstract: Many headsets include automatic noise cancellation (ANC) which dramatically reduces perceived background noise and improves user listening experience. Unfortunately, the voice microphones in these devices often capture ambient noise that the headsets output during phone calls or other communication sessions to other users. In response, many headsets and communication devices provide manual muting circuitry, but users frequently forget to turn the muting on and/or off creating further problems as they communicate. To address this, the present inventors devised, among other things, an exemplary headset that detects the absence or presence of user speech, automatically muting and unmuting the voice microphone without user intervention. Some embodiments leverage relationships between feedback and feedforward signals in ANC circuitry to detect user speech, avoiding the addition of extra hardware to the headset.

Abstract: A method of operating a headphone configured to be removed from and placed in close proximity to a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the headphone to operate in 5 a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the headphone to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

Abstract: A method of operating a headphone configured to be removed from and placed in close proximity to a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the headphone to operate in 5 a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the headphone to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

Abstract: The disclosure includes a voice isolation system comprising an acoustic echo-cancelation subsystem configured to receive a plurality of input signals, subtract an interference component from the input signals, and provide a plurality of output signals. The system also includes an adaptive beamformer subsystem configured to receive the plurality of output signals from the acoustic echo-cancelation subsystem and compute a signal-to-noise ratio enhanced signal based on the received output signals. The system also includes a residual noise suppressor subsystem configured to attenuate at least one portion of the SNR enhanced signal received from the adaptive beamformer subsystem based on the at least one portion having an SNR below a predetermined SNR threshold. The system also includes an automatic gain control subsystem configured to process a signal outputted from the residual noise suppressor subsystem and transmit a resulting signal as an output signal.

Abstract: An apparatus can include an audio playback device configured to provide an audio output to a user, and a controller configured to: receive an initial playback position within the audio output; determine that an off-ear event has occurred; identify a time corresponding to the off-ear event; instruct the audio playback device to pause the audio output at the identified time; and calculate a new playback position within the audio output based at least in part on the identified time.

Abstract: An amplifier for headphones including a current digital-to-analog converter (DAC) configured to output a current based on a digital audio input signal, an output electrically connected to a speaker and configured to output an output signal to the speaker, and a pulse width modulation (PWM) loop configured to receive an error signal, the error signal based on a difference between the current from the current DAC and a current of the output signal, and generate the output signal based on the error signal. The PWM loop includes an analog-to-digital converter (ADC) configured to receive an analog signal based on the current from the current DAC and output a digital signal representing the analog signal, and an encoder configured to receive the digital signal and output a pulse having a width based on the analog signal.

Abstract: The disclosure includes a headset including one or more earphones and a connector configured to couple data and charge between the headset and a user equipment (UE). The headset also includes a charge node. The charge node includes a charge port for receiving UE charge from a charge source. The charge node also includes a downstream port for coupling audio data toward the earphones. The charge node further includes an upstream port for coupling the audio data toward the earphones via the downstream port and coupling UE charge from the charge port toward the UE via the connector.

Abstract: The disclosure includes a headset comprising one or more earphones including one or more sensing components. The headset also includes one or more voice microphones to record a voice signal for voice transmission. The headset also includes a signal processor coupled to the earphones and the voice microphones. The signal processor is configured to employ the sensing components to determine a wearing position of the headset. The signal processor then selects a signal model for noise cancellation. The signal model is selected from a plurality of signal models based on the determined wearing position. The signal processor also applies the selected signal model to mitigate noise from the voice signal prior to voice transmission.

Abstract: A method of operating a headphone configured to be removed from and placed in close proximity to a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the headphone to operate in a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the headphone to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

Abstract: Disclosed is a signal processor for headphone off-ear detection. The signal processor includes an audio output to transmit an audio signal toward a headphone speaker in a headphone cup. The signal processor also includes a feedback (FB) microphone input to receive a FB signal from a FB microphone in the headphone cup. The signal processor also includes an off-ear detection (OED) signal processor to determine an audio frequency response of the FB signal over an OED frame as a received frequency response. The OED processor also determines an audio frequency response of the audio signal times an off-ear transfer function between the headphone speaker and the FB microphone as an ideal off-ear response. A difference metric si generated comparing the received frequency response to the ideal off-ear frequency response. The difference metric is employed to detect when the headphone cup is disengaged from an ear.

Abstract: An audio processing system can include an Analog to Digital Converter structured to receive an analog input signal and convert the analog input signal to a digital input signal, a first processor coupled with the Analog to Digital Converter, the first processor including at least one programmable bi-quadratic filter chain structured to receive the digital input signal from the Analog to Digital Converter and perform audio processing on the received digital input signal at a first clock rate, and a second processor coupled with the first processor and the Analog to Digital Converter and structured to receive the digital input signal from the Analog to Digital Converter and perform audio processing on the received digital input signal at a second clock rate that is different from the first clock rate.

Abstract: A system including an automatic noise canceling (ANC) headphone and a processor. The ANC headphone has a microphone configured to generate a microphone signal and at least two non-zero ANC gain levels. The processor is configured to receive the microphone signal, determine a characteristic of the microphone signal, and identify a revised ANC level from the ANC gain levels based on a comparison of the characteristic to at least one threshold. Methods are also disclosed.

Abstract: A headphone having a speaker, a feedforward microphone, a feedback microphone, and an OED processor. The speaker is configured to transmit an audio playback signal based on a headphone audio signal. The feedforward microphone is configured to sense an ambient noise signal and transmit a feedforward microphone signal based at least in part on the ambient noise signal. The feedback microphone is configured to sense a total audio signal and transmit a feedback microphone signal based at least in part on the total audio signal, in which the total audio signal is the sum of the audio playback signal and at least a portion of the ambient noise level. The OED processor is configured to determine whether the headphone is off ear or on ear, based at least in part on the headphone audio signal, the feedforward microphone signal, and the feedback microphone signal.

Abstract: A system for operating a headphone can include a primary processor to control the headphone and operate in a low-power state, a cup portion having a microphone to receive an input, a listening sub-system to convert the input into an output signal, and a neural net processor to receive the output signal from the listening sub-system and determine whether to generate a wake signal based on the received output signal.

Abstract: A system includes at least one processor and at least one memory storing program instructions that, when executed by the at least one processor, cause the system to send an acoustic ranging transmitter signal between a plurality of calibration reference positions and at least one anchor point, receive an acoustic ranging receiver signal associated with the acoustic ranging transmitter signal and with distances between the plurality of calibration reference positions and the at least one anchor point, and estimate a speed of sound based on the acoustic ranging receiver signal.

Abstract: A system for operating an earbud can include a primary processor to control the earbud and operate in a low-power state, a microphone to receive an input, a casing having a speaker configured to provide audio output from the primary processor to a user's ear, the casing being configured to maintain a position in a user's ear canal to maintain a position of the speaker within the user's ear, a listening sub-system to convert the input into an output signal, and a neural net processor to receive the output signal from the listening sub-system and determine whether to generate a wake signal based on the received output signal.

Abstract: A method of operating a personal audio device configured to be removed from and inserted into a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the personal audio device to operate in a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the personal audio device to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

Abstract: A low power, digital audio interface includes support for variable length coding depending on content of the audio data sent from the interface. A particularized coding system is implemented that uses techniques of silence detection, dynamic scaling, and periodic encoding to reduce sent data to a minimum. Other techniques include variable packet scaling based on an audio sample rate. Differential signaling techniques are also used. The digital audio interface may be used in a headphone interface to drive digital headphones. A detector in the interface may detect whether digital or analog headphones are coupled to a headphone jack and drive the headphone jack accordingly.

Abstract: The disclosure includes an acoustic processing network comprising a Digital Signal Processor (DSP) operating at a first frequency and a Real-Time Acoustic Processor (RAP) operating at a second frequency higher than the first frequency. The DSP receives a noise signal from at least one microphone. The DSP then generates a noise filter based on the noise signal. The RAP receives the noise signal from the microphone and the noise filter from the DSP. The RAP then generates an anti-noise signal based on the noise signal and the noise filter for use in Active Noise Cancellation (ANC).