A nonlinear control system and a speaker protection system are disclosed. In particular, a control system for adapting an audio output from a speaker in the proximity of an object is disclosed. The controller is configured to accept one or more input signals, and one or more estimated states produced by the model to produce one or more control signals. A speaker protection system and a quality control system are disclosed. More particularly, a system for clamping the input to a speaker dependent upon an estimate of the proximity, acoustic volume, and/or acoustic coupling of the speaker to a nearby object is disclosed.

The Application relates to optically transparent electrostatic transducers. In some embodiments, the transducers comprise graphene. Such transducers are capable of functioning as acoustic sensors and/or transmitters as a singulated device or in an array configuration. Also provided are methods of manufacturing and using such transducers.

A method for determining a direct current impedance of a transducer may include receiving an input signal indicative of an electrical power consumed by the transducer and calculating, by a thermal model of the transducer, the direct current impedance based on the electrical power.

A display device includes a display panel including a display layer including light-emitting elements disposed on a substrate, and a sensor electrode layer disposed on the display layer. The sensor electrode layer includes a first sound electrode and a second sound electrode; a vibration layer electrically contacting the first sound electrode and the second sound electrode and being deformed in response to a first sound driving voltage applied to the first sound electrode and a second sound driving voltage applied to the second sound electrode; and sensor electrodes disposed on the vibration layer. The sensor electrodes sense an input.

A microphone system, comprises a first transducer, for generating a first acoustic signal, and a second transducer, for generating a second acoustic signal. A high-pass filter receives the first signal and generates a first filtered signal, and a low-pass filter receives the second signal and generates a second filtered signal. An adder forms an output signal of the microphone system as a sum of the first filtered signal and the second filtered signal.

Monitoring circuitry, comprising: a current monitoring unit operable to monitor a speaker current flowing through a speaker and generate a monitor signal indicative of that current; and a controller operable, based on a control signal, to control the current monitoring unit to control whether the monitor signal is generated and/or a property of the monitor signal.

Briefly, in accordance with one or more embodiments, a headphone device, comprises at least one ear muff comprising a structure to hold the at least one ear muff against an ear of a user, and at least one driver disposed in the at least one ear muff. An earbud comprises an earbud housing having a protrusion to fit into an external acoustic meatus or ear canal of a user, and a driver disposed in the earbud housing. The driver comprises an electrostatic acoustic transducer comprising a substrate comprising a first material to function as a first electrode, a dielectric layer coupled with the first material, wherein the dielectric layer has one or more cavities formed therein, and a membrane coupled with the dielectric layer to cover the one or more cavities and to function as a second electrode.

A diaphragm assembly for a miniature acoustical transducer having a sufficiently light paddle to allow good audio performance and a sufficiently stiff frame to allow handling. The paddle may be made of a thin sheet of aluminium and the frame of thicker aluminium or a bent sheet of aluminium.

Example embodiments may include one or more of receiving sound emissions signals from channels via sound emitters, controlling the sound emission signals, via relay circuits, and one of the relay circuits is configured to interrupt one of the sound emission signals associated with one of the sound emitters while the other sound emissions signals pass to the other corresponding sound emitters, and receiving, via a sound detection circuit, an electrical ambient sound signal based on ambient sound sensed by the one of the sound emitters responsive to the interrupted one of the sound emission signals.

A control circuit includes: a voltage output circuit control unit that controls a voltage output circuit so as to apply a voltage, which corresponds to an output control signal and is to cause an electrostatic transducer to generate vibration, sound, or pressure, between both ends of the electrostatic transducer in a case where a detection control signal is at a first level, and that stops the voltage output circuit in a case where the detection control signal is at a second level; a pulse signal output unit that outputs a pulse signal, which is to cause the electrostatic transducer to detect vibration, sound, or pressure, to a terminal on a high potential side of the electrostatic transducer via a diode; and a voltage clamp unit that outputs a clamp voltage acquired by clamping of a voltage between the terminals of the electrostatic transducer to a predetermined voltage or lower.