Knowles Electronics, Inc.

Sarmad Qutub

Robert A Popper

Dibyendu Nandy

Oddy Nopporn Khamharn

Henrik Thomsen

William A Ryan

Ramanujapuram Raghuvir

Yang Li

Paul Fielding Smith

Michael Pate

Martin Volk

Thibault Kassir

A microphone that includes a calibration signal generator that generates a calibration signal based upon a received invocation input. The calibration signal has known audio properties. The microphone also includes a transducer that converts sound energy into an electrical signal. An integrated circuit receives the electrical signal from the transducer. An external microphone interface provides the calibration signal to a device external to the microphone.

Audio calibration using a microphone

At least one electrical value for a plurality of frequencies is measured over a range of frequencies. An impedance is calculated based upon the at least one electrical value for each of the plurality of frequencies in the frequency range, the calculating producing a plurality of impedances. A maximum impedance from the plurality of impedances and a frequency associated with the maximum impedance are determined. The frequency is compared to a predetermined threshold, and based upon the comparing it is determined whether an earphone has been removed from the ear of a wearer.

Apparatus and method for detecting earphone removal and insertion

A microphone system includes a first transducer deployed at a first microphone; a second transducer deployed at a second microphone, the first microphone being physically distinct from the second microphone; a decimator deployed at the second microphone that receives first pulse density modulation (PDM) data from the first transducer and second PDM data from the second transducer and decimates and combines the first PDM data and the second PDM data into combined pulse code modulation (PCM) data; and an interpolator deployed at the second microphone for converting the combined PCM data to combined PDM data, and transmits the combined PDM data to an external processing device.

Interface for microphone-to-microphone communications

An analog signal is received from an acoustic transducer. The analog signal is converted into digital data. A determination is made as to whether acoustic activity exists within the digital data. The digital data is stored in a temporary memory storage device and a count is maintained of an amount of digital data in the temporary memory storage device. When the count exceeds a predetermined threshold, at least some of the digital data is transmitted from the temporary memory storage device to a processor.

Low power voice trigger for acoustic apparatus and method

A method of operating an acoustic system includes detecting an ultrasonic sound signal and pattern matching the received ultrasonic sound signal to determine when the received ultrasonic sound signal is a desired ultrasonic sound signal. The method includes sending a signal to at least one electronic component when the received ultrasonic sound signal is the desired ultrasonic sound signal. The method includes operating the microphone in a lower power state when the received ultrasonic sound signal is not the desired ultrasonic sound signal.

Low power acoustic apparatus and method of operation

An external clock signal having a first frequency is received. A division ratio is automatically determined based at least in part upon a second frequency of an internal clock. The second frequency is greater than the first frequency. A decimation factor is automatically determined based at least in part upon the first frequency of the external clock signal, the second frequency of the internal clock signal, and a predetermined desired sampling frequency. The division ratio is applied to the internal clock signal to reduce the first frequency to a reduced third frequency. The decimation factor is applied to the reduced third frequency to provide the predetermined desired sampling frequency. Data is clocked to a buffer using the predetermined desired sampling frequency.

Decimation synchronization in a microphone

First analog signals are received from a first microphone, converted into first digital data and stored in a first buffer. A determination is made as to whether voice activity has occurred when voice activity is determined, a voice activity detect signal is sent to an external processor. The external processor responsively provides an exterior clock signal upon receiving the voice activity detect signal. Second analog signals are received from a second microphone, converted into second digital data and stored in a second buffer. The first digital data in the first buffer is not necessarily synchronized in real time with the second digital data in the second buffer. The first digital data from the first buffer and the second digital data from the second buffer is decimated using the external clock to provide decimated output data, the decimated output data having the first digital data and the second digital data aligned in real time.

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Des Plaines, IL, United States of America

Sarmad Qutub