Abstract: A headphone detector including a headphone and a processor. The headphone has a microphone and a speaker, and the microphone is configured to generate an audio signal based on an output of the speaker. The processor is configured to receive the audio signal, determine a characteristic of the audio signal, and assess whether the headphone is on ear or off ear based on a comparison of the characteristic to a threshold. The threshold corresponds to one or more of an audio response of the audio signal at a corresponding frequency and an audio response of a feedback microphone signal at a corresponding frequency, under one or more known conditions.

Abstract: Embodiments of the invention include an oversampling Analog to Digital Converter that uses uneven non-overlapping clock phases to reduce switched capacitor circuit power consumption. A return-to-zero sub phase of one of the clock phases may also be used for feedback reference capacitors. A delay lock loop may be combined with the non-overlapping clock phase generator to control accurate timing.

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: A speaker system includes a case, an audio input, speakers, an accelerometer, and a computer processor. The audio input is structured to receive a program audio signal from an audio device. The speakers are configured to play an audio output based on the program audio signal, the audio output causing a vibration of the case. The accelerometer is configured to detect the vibration of the case as well as a user tap on the case. The computer processor is configured to identify a user gesture that includes the tap on the case, to identify the tap apart from the case vibration by processing the detected vibration of the case and the detected user tap on the case based on information from the program audio signal to separate the detected user tap from the detected vibration, and to commence a particular function associated with the user gesture.

Abstract: A portable speakerphone having a housing, a receiving transducer, an electrical cable, a transmitting transducer, and a processor. The receiving transducer is affixed to the housing and is configured to receive a first electrical signal from a mobile device. The electrical cable is coupled to and extends from the housing. The transmitting transducer is affixed to the electrical cable, remote from the housing. Also, the transmitting transducer is configured to transmit a second electrical signal, and the second electrical signal is based in part on the first electrical signal. The processor is configured to suppress acoustic echo by modifying the second electrical signal. The processor is also configured to output the modified second electrical signal to the mobile device. A related method is also disclosed.

Abstract: The disclosure includes an analog to digital converter (ADC). The ADC includes a comparator to compare sample values of an analog signal in an analog domain to reference values to determine digital values in a digital domain. The digital values correspond to the analog signal and may be determined according to successive approximation. The ADC also includes chop switches to modulate the analog signal to increase a frequency of flicker noise in the analog domain. The ADC also includes an un-chop switch to demodulate the digital values in the digital domain prior filtration of the flicker noise by a digital filter.

Abstract: The disclosure includes a mechanism for mitigating charge related disturbances in a Successive Approximation Register (SAR) Analog to Digital Converter (ADC) by providing a fine reference connection and a rough reference connection. A switch array is activated to couple a current bit capacitor of a capacitor array to the rough reference connection while a current bit corresponding to the current bit capacitor is determined by a comparator. The switch array is further activated to couple a previous bit capacitor of the capacitor array to the fine reference connection while the current bit capacitor is coupled to the rough reference connection. This separates charge flow on the rough reference connection from capacitors coupled to the fine reference connection.

Abstract: The disclosure includes a mechanism for mitigating electrical current leakage in a Successive Approximation Register (SAR) Analog to Digital Converter (ADC) by using a Flash ADC in conjunction with the SAR ADC. A sequence controller in the SAR ADC uses the output of the Flash ADC to control a switch array. Depending on the output of the Flash ADC, the sequence controller can control the switch array to couple at least one capacitor in the capacitor network of the SAR ADC to a voltage that reduces charge leakage in the SAR ADC. The voltage may be a pre-defined positive or negative reference voltage.

Abstract: A method for re-forming a complete ring network of a plurality of Bluetooth® speakers, after a speaker has left an original ring of speakers, the method including detecting that the speaker has left the ring, and reestablishing the ring without the departed speaker. The detection may include a timeout detection if the speaker left without notice, or include receiving notice that the speaker intends to leave.

Abstract: A circuit can have a low mirror input voltage and fast settling while providing a large current mirror gain. The circuit can include a current source, a first current mirror device having a first transistor and a second transistor and electrically coupled with the current source, a third transistor electrically coupled with the first transistor, a second current mirror device having a fourth transistor and a fifth transistor and electrically coupled between the third transistor and the second transistor, and an output device electrically coupled with the first and second current mirror devices.

Abstract: A system can include an analog input port; a digital output port; and a successive approximation register (SAR) analog-to-digital converter (ADC). The SAR ADC can include a voltage comparator Vd having a first input, a second input, and an output; a first plurality of capacitors Cp[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; a second plurality of capacitors Cn[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; and a SAR controller coupled between the output of the voltage comparator Vd and the digital output port.

Abstract: A new compensation system for an audio input reduces noise by matching feedback ratios in the positive and negative paths. A variable resistance network allows for fine control of resistance trimming in one of the signal paths, which allows for compensation between tolerance of resistors that are external to an integrated circuit and those that are internal to the integrated circuit.

Abstract: An adaptive noise canceling system can include a noise cancellation processor having an audio input for receiving an input audio signal, a microphone input structured to receive one or more microphone signals from a monitored environment, and a filter processor structured to produce a filtering function based on one or more filter parameters. The system can also include an adaptivity processor structured to change the one or more filter parameters in the noise cancellation processor based on a changing operating environment of the adaptive noise canceling system.

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, identify a revised ANC level from the ANC gain levels based on a comparison of the characteristic to at least one threshold, and output a signal corresponding to the revised ANC level. Methods are also disclosed.

Abstract: A headphone detector including a headphone and a processor. The headphone has a microphone and a speaker, and the microphone is configured to generate an audio signal based on an output of the speaker. The processor is configured to receive the audio signal, determine a characteristic of the audio signal, and assess whether the headphone is on ear or off ear based on a comparison of the characteristic to a threshold. The threshold corresponds to one or more of an audio response of the audio signal at a corresponding frequency and an audio response of a feedback microphone signal at a corresponding frequency, under one or more known conditions.

Abstract: A system can include a digital oversampler configured to oversample an input data stream; a rate generator configured to select a frequency that is not less than an expected frequency of the input data stream; a rate generator clock of the rate generator configured to output a clock signal that has the selected frequency; a sample receiver configured to receive at least one sample of the input data stream from the digital oversampler; a sample counter configured to be incremented by each received sample responsive to a determination that the sample receiver has received at least one sample of the input data stream from the digital oversampler; a sample rate converter configured to accumulate samples from the sample receiver at the rate of a “toothless” clock signal, wherein the sample counter is configured to be decremented by the “toothless” clock signal at the selected frequency responsive to a determination that the sample receiver has not received at least one sample of the input data stream from the digi

Abstract: A case having a recessed holding, an acoustic waveguide, and at least one audio transducer device. The recessed holding well is configured to receive and captively hold a stand-alone keyboard within the recessed holding well. The acoustic waveguide is integrated with a bottom cover of the case and between a bottom surface of the case and the recessed holding well. The at least one audio transducer device is coupled to a signal processing device and the acoustic waveguide. The at least one audio transducer device is configured to generate an audible audio output in response to an audio signal output from the signal processing device. The acoustic waveguide is configured to receive the audible audio output and generate an enhanced bass audio output.

Abstract: A method for forming a complete ring network of a plurality of Bluetooth® speakers, the method including populating a configurable speaker register of each of the plurality of Bluetooth® speakers with an address of an upstream Bluetooth® speaker that is in the plurality of Bluetooth® speakers, populating the configurable speaker register of each of the plurality of Bluetooth® speakers with an address of a downstream Bluetooth® speaker that is in the plurality of Bluetooth® speakers, and coupling an audio source to one Bluetooth® speaker of the plurality of Bluetooth® speakers.

Abstract: The disclosure includes an analog to digital converter (ADC) comprising a successive approximation register (SAR) unit including a capacitive network to take a sample of an analog signal and a comparator to approximate a digital value based on the analog signal sample via successive comparison. The disclosure also includes a programmable sequencer. The sequencer includes a control memory containing control signal states indicating control signals to operate the SAR unit. The sequencer also includes a program memory including sequence instructions defining a duty cycle for the SAR unit by referencing the control signal states in the control memory. The sequencer also includes a processing circuit to apply control signals according to the control signal states in an order defined by the sequence instructions to manage a sequence of operations at the SAR unit according to the duty cycle to control the ADC.

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.