Disclosed herein is a sound reproduction system configured to emit a first sound and a second sound from a loudspeaker at a time. The first sound is intended to reach ears of an object person's. The second sound is intended to reach ears of a non-object person's and compliant with a control characteristic. The control characteristic is defined such that the second sound includes a component which is emitted from the loudspeaker toward a first region occupied by the object person and has a sound pressure lower than a predetermined value, and another component which is emitted from the loudspeaker toward a second region occupied by the non-object person and has a sound pressure equal to the predetermined value.

An apparatus to time delay a digital, signal output from an oversampled sensor includes a first time delay element and a second time delay element. The first time delay element has a first input and a first output. The first time delay element is configured to output a time delayed signal that is time delayed by an integer number of sampling clock cycles. An output of the oversampled sensor is connected to the first input of the first time delay element. The second time delay element has a second input and a second output and is configured to output a time delayed signal that is time delayed by an integer number of sampling clock cycles. The first output of the first time delay element is connected to the second input of the second time delay element. A multiplexer has a control input and a multiplexer output. The first output of the first time delay element is connected to a first multiplexer input. The second output of the second time delay element is connected to a second multiplexer input. In operation, time delay information is used to provide a signal to the control input to select a particular multiplexer input for output on the multiplexer output. The output of the oversampled sensor is time delayed by an amount provided by the particular multiplexer input.

Programming time delay data in an oversampled sensor includes determining whether to enter Programming Mode based on a value of a system parameter received by the oversampled sensor. Programming Mode is entered when the value of the system parameter corresponds to Programming Mode. The time delay data is programmed in the oversampled sensor during Programming Mode. The oversampled sensor uses the time delay data to time delay its output in an oversampled domain. Programming Mode is exited after a predetermined time has expired relative to when Programming Mode was entered. The system parameter can be a frequency of a sampling clock signal.

Disclosed herein is a sound reproduction system configured to emit a first sound and a second sound from a loudspeaker at a time. The first sound is intended to reach ears of an object person's. The second sound is intended to reach ears of a non-object person's and compliant with a control characteristic. The control characteristic is defined such that the second sound includes a component which is emitted from the loudspeaker toward a first region occupied by the object person and has a sound pressure lower than a predetermined value, and another component which is emitted from the loudspeaker toward a second region occupied by the non-object person and has a sound pressure equal to the predetermined value.

A piezoelectric driver (10) includes n piezoelectric layers (3A to 3D) (where n is an integer equal to or greater than 2) that are stacked, with electrode layers (4B to 4D) each interposed between any adjacent piezoelectric layers, and with electrode layers (4A and 4E) further formed underneath the lowermost piezoelectric layer (3A) and on top of the uppermost piezoelectric layer (3D), and the piezoelectric driver (10) is bent and displaced in the direction in which the piezoelectric layers are stacked. A signal converter (11) converts an n-bit digital signal (IS) into n bits of a bit string data signal (BS) comprising of bit data indicating whether a drive voltage to be applied to each of the piezoelectric layers (3A to 3D) via the electrode layers (4A to 4B) is on or off. An output device (12) outputs, in accordance with values of the individual bits in the bit string data signal (BS) provided through conversion performed by the signal converter (11), drive voltages to be applied to the individual piezoelectric layers (3A to 3D).

A digital loudspeaker includes a substrate, a first stator fixed with respect to the substrate, a second stator fixed with respect to the substrate and spaced at a distance from the first stator, and a membrane between the first stator and the second stator. The membrane is displaceable between a first position in which the membrane mechanically contacts the first stator and a second position in which the membrane mechanically contacts the second stator. The first stator and the second stator are arranged to electrostatically move the membrane from a rest position spaced apart from the first position and the second position to the first position and the second position, respectively.

The present invention is in the field of programmable pulse width modulator (PWM) controller comprising filters and a mixer, such as for use in a digital audio converter and digital amplifier controller, a chip comprising said PWM controller, a device comprising said PWM controller or said chip, as well as uses thereof.

Acoustic listening methods, devices, and systems herein relate to auscultation of a body. An auscultation device as disclosed herein can be operable to function within a cavity of the body, and can operate in conjunction with other auscultation devices, including with eternal auscultation devices. Individual devices and grouped devices can operate with the addition of a computing device.

The invention is a multi-microphone voice processing SoC primarily for head worn applications. It bypasses the use of conventional pre-amp voice CODEC (ADC/DAC) chips all together by replacing their functionality with digital MEMS microphone(s) and digital speaker driver (DSD). Functionality necessary for speech recognition such as noise/echo cancellation, speech compression, speech feature extraction and lossless speech transmission are also integrated into the SoC. One embodiment is a noise cancellation chip for wired, battery powered headsets and earphones, as smart-phone accessory. Another embodiment is as a wireless Bluetooth noise cancellation companion chip. The invention can be used in headwear, eyewear glass, mobile wearable computing, heavy duty military, aviation and industrial headsets and other speech recognition applications in noisy environments.

An operable membrane device is provided, including a plate, a plurality of membranes suspended from the plate and being a seat of residual mechanical constraints, at least a first actuator configured to deform the plate outside its plane, second actuators, each second actuator being configured to deform a membrane outside its plane, and control electronics configured to generate second control signals at the second actuators in order to vibrate the membranes and configured to generate first control signals at the first actuator to cause a deformation of the plate so that the plate is found in the deformed state, wherein a mechanical constraint is applied to the membranes that at least reduces the residual constraints of the membranes.