Abstract: A system and method for passively balancing electroacoustic transducers so that sounds other than the transducer's output can be detected. A transducer producing audio output based upon an input audio signal can operate in reverse to produce a signal in response to the impact of external sound upon the transducer from another source. This “reverse” or “microphone” signal represents the sound from the other source. Transducers are operated in monophonic mode, each in opposite polarity to the other thus canceling out and leaving only the microphone signal created by the transducers, i.e., a signal representing the external sound. The microphone signal can be amplified, and can be filtered and processed to identify and/or obtain various types of information about the sound received by the transducers.

Abstract: A system and method for passively balancing electroacoustic transducers so that sounds other than the transducer's output can be detected. A transducer producing audio output based upon an input audio signal can operate in reverse to produce a signal in response to the impact of external sound upon the transducer from another source. This “reverse” or “microphone” signal represents the sound from the other source. Transducers are operated in monophonic mode, each in opposite polarity to the other thus canceling out and leaving only the microphone signal created by the transducers, i.e., a signal representing the external sound. The microphone signal can be amplified, and can be filtered and processed to identify and/or obtain various types of information about the sound received by the transducers.

Abstract: A method of controlling a mobile device is described, the method comprising: receiving a time varying current or voltage of a signal generated on the terminals of an acoustic transducer of the mobile device, the time varying current or voltage being generated in response to a tapping and/or sliding motion on a surface of the mobile device performed by a user; comparing the time varying signal characteristics with a set of predetermined signal characteristics; and generating at least one user command in dependence of the comparison. The mobile device may reliably detect complex user commands using an acoustic transducer.

Abstract: A method of controlling a mobile device is described, the method comprising: receiving a time varying current or voltage of a signal generated on the terminals of an acoustic transducer of the mobile device, the time varying current or voltage being generated in response to a tapping and/or sliding motion on a surface of the mobile device performed by a user; comparing the time varying signal characteristics with a set of predetermined signal characteristics; and generating at least one user command in dependence of the comparison. The mobile device may reliably detect complex user commands using an acoustic transducer.

Abstract: A system for producing a mechanical haptic pattern based on linear resonance actuator (LRA) signal is disclosed. The system includes an actuator displacement sensor, the actuator displacement sensor configured to apply an alternating measurement signal at a predetermined frequency to an actuator motor. The actuator displacement sensor configured to use a measure of a voltage across and a current through the actuator motor to determine its impedance at the predetermined frequency and determine an estimated displacement of the actuator motor using said impedance and a predetermined displacement-impedance function. The system also includes a controller configured to accept the LRA signal and the estimated displacement, wherein the controller is configured to alter the input LRA signal according to the estimated displacement to limit excursion of a moving part of the actuator motor.

Abstract: An approach is disclosed for achieving improved sound quality from mobile ‘hifi’ playback devices by driving compatible headphones in ‘balanced’ or ‘differential’ mode via standard size headphone connectors, while retaining full compliance with legacy jack connections and allowing use of a microphone. When a headphone is connected, a smartphone may determine whether the headphone is one capable of accepting balanced audio signals, or one that uses a conventional 4-pole CTIA or OMTP jack. For a headphone that accepts balanced audio signals, the four poles of a 4-pole jack are used to drive left and right audio channels, and inverted left and right audio channels. For conventional 4-pole jacks, switches in the smartphone adapt the audio output signals to the configuration expected by the headphone and allow the smartphone to receive input from the microphone. A switch may be used to alternate between the balanced and conventional CTIA or OMTP mode.

Abstract: A system for producing a mechanical haptic pattern based on linear resonance actuator (LRA) signal is disclosed. The system includes an actuator displacement sensor, the actuator displacement sensor configured to apply an alternating measurement signal at a predetermined frequency to an actuator motor. The actuator displacement sensor configured to use a measure of a voltage across and a current through the actuator motor to determine its impedance at the predetermined frequency and determine an estimated displacement of the actuator motor using said impedance and a predetermined displacement-impedance function. The system also includes a controller configured to accept the LRA signal and the estimated displacement, wherein the controller is configured to alter the input LRA signal according to the estimated displacement to limit excursion of a moving part of the actuator motor.

Abstract: A voice coil motor displacement sensor and a voice coil motor controller that uses said sensor. The sensor configured to apply an alternating measurement signal at a predetermined frequency to a voice coil motor, the sensor configured to use a measure of a voltage across and a current through the voice coil motor to determine its impedance at the predetermined frequency and determine an estimated displacement of said voice coil motor using said impedance and a predetermined displacement-impedance function.

Abstract: One example discloses an acoustic pairing device, comprising: an acoustic processor configured to receive a first acoustic signal and a second acoustic signal; a signal comparison module configured to identify a propagation delay or amplitude difference between the first and second acoustic signals; and a pairing module configured to output a pairing signal if the propagation delay or amplitude difference is between a first value and a second value. Another example discloses a method for acoustic pairing between a first device and a second device, executed by a computer programmed with non-transient executable instructions, comprising: receiving a propagation delay or amplitude difference between a first acoustic signal and a second acoustic signal; pairing the first and second devices if the propagation delay or amplitude difference is between a first value and a second value.

Abstract: One example discloses an acoustic pairing device, comprising: an acoustic processor configured to receive a first acoustic signal and a second acoustic signal; a signal comparison module configured to identify a propagation delay or amplitude difference between the first and second acoustic signals; and a pairing module configured to output a pairing signal if the propagation delay or amplitude difference is between a first value and a second value. Another example discloses a method for acoustic pairing between a first device and a second device, executed by a computer programmed with non-transient executable instructions, comprising: receiving a propagation delay or amplitude difference between a first acoustic signal and a second acoustic signal; pairing the first and second devices if the propagation delay or amplitude difference is between a first value and a second value.

Abstract: A voice coil motor displacement sensor and a voice coil motor controller that uses said sensor. The sensor configured to apply an alternating measurement signal at a predetermined frequency to a voice coil motor, the sensor configured to use a measure of a voltage across and a current through the voice coil motor to determine its impedance at the predetermined frequency and determine an estimated displacement of said voice coil motor using said impedance and a predetermined displacement-impedance function.