Abstract: A capacitive sensor includes a first conductive structure; a second conductive structure that is counter to the first conductive structure, wherein the second conductive structure is movable relative to the first conductive structure in response to an external force acting thereon, wherein the second conductive structure is capacitively coupled to the first conductive structure to form a first capacitor having a first capacitance that changes with a change in a distance between the first conductive structure and second conductive structure; a signal generator configured to apply a first electrical signal step at an input or at an output of the first capacitor to induce a first voltage transient response at the output of first capacitor; and a diagnostic circuit configured to detect a fault in the capacitive sensor by measuring a first time constant of the first voltage transient response and detecting the fault based on the first time constant.

Abstract: A device includes a micro-electromechanical system (MEMS) element configured to sense acoustic signals. The device also includes a circuitry configured to enable the microphone element to sense the acoustic signals. The circuitry is further configured to disable the microphone element to prevent the microphone element to sense the acoustic signals. It is appreciated that the circuitry is further configured to apply a test signal to the MEMS element when the microphone element is disabled. The microphone element outputs a signal in response to the test signal to the circuitry. The circuitry in response to the output signal with a first value determines that a diaphragm of the MEMS element is nonoperational and the circuitry in response to the output signal with a second value determines that the diaphragm of the MEMS element is operational.

Abstract: Embodiments of the present application provide acoustic wave signal reading apparatuses, acoustic wave signal reading circuits, and control methods thereof related to the field of acoustic wave signal reading technology. One embodiment of an acoustic wave signal reading circuit comprises: an acoustic wave receiver, a reset control circuit, a function circuit, and an output circuit; an acoustic wave receiver is configured to convert a received acoustic wave signal into an electrical signal and outputs the electrical signal to a first node; the reset control circuit outputs a voltage to the first node; the function circuit switches states based on the first node, a signal terminal, and a voltage terminal, and outputs a voltage to a second node to reset the second node or amplifies a potential of the first node and outputs to the amplified potential to the second node depending on a state of the function circuit.

Abstract: An electronic device includes a chassis, a microphone hole penetrating an outer wall of the chassis, and a microphone module that faces the microphone hole. The microphone module has a microphone that obtains sound information outside the chassis through the microphone hole, a flexible substrate laminated on a back surface of the microphone, a metallic plate laminated on a back surface of the flexible substrate, and a sound hole opened in the back surface of the microphone and penetrating the flexible substrate and the metallic plate. The electronic device further includes a double-sided tape fastened to a first region, surrounding the sound hole, of a back surface of the metallic plate, and to an inner surface of the chassis, and that fixes the microphone module to the chassis, and a conductive member that electrically connects the second region of the metallic plate and the inner surface of the chassis.

Abstract: Evaluating an implanted hearing prosthesis, including operating the implanted hearing prosthesis, capturing sound generated by a transducer of the prosthesis during said operation, and comparing the captured sound to a sound model.

Abstract: A MEMS microphone includes a MEMS transducer, a sealing cover, and a package substrate. The MEMS transducer includes an element substrate, a plurality of cantilevered beams, and a weight. An airtight sealing structure is formed with the sealing cover and the package substrate, which is formed by mounting the MEMS transducer on the package substrate, and adhering the sealing cover to the package substrate so as to surround the MEMS transducer.

Abstract: A method of making a sensing unit for a sensing system of a vehicle includes providing a first housing portion, a second housing portion, and a transducer having a piezo element. The transducer is placed in the first housing portion at the closed transducer end of the first housing portion. A dampening ring is disposed in the first housing portion between the closed transducer end and the first open receiving end of the first housing portion. A compression ring is provided and disposed at least partially into the first open receiving end of the first housing portion with wires electrically connecting the piezo element to the pins of the compression ring in the first housing portion. A PCB is disposed in the second housing portion and electrically connected to terminals of a connector portion of the second housing portion. The first housing portion is attached to the second housing portion.

Abstract: A loudspeaker system is provided including an enclosure and a transducer mounted within the enclosure. A port is provided in the enclosure, the port having an inlet located at an external surface of the enclosure and an outlet located in an interior of the enclosure which allow bi-directional air flow in and out of the enclosure. At least one duct is provided in the port to extract air flow from the port and redirect the air flow within the enclosure. In one embodiment, the at least one duct may comprise a NACA duct.

Abstract: A MEMS may include a backplate comprising first and second electrodes electrically isolated from one another and mechanically coupled to the backplate in a fixed relationship relative to the backplate, and a diaphragm configured to mechanically displace relative to the backplate as a function of sound pressure incident upon the diaphragm. The diaphragm may comprise third and fourth electrodes electrically isolated from one another and mechanically coupled to the diaphragm in a fixed relationship relative to the diaphragm such that the third and fourth electrodes mechanically displace relative to the backplate as the function of the sound pressure. The first and third electrodes may form a first capacitor, the second and fourth electrodes may form a second capacitor, and the first capacitor may be configured to sense a displacement of the diaphragm responsive to which the second capacitor may be configured to apply an electrostatic force to the diaphragm to return the diaphragm to an original position.

Abstract: A device is disclosed to reduce noise and temperature during measurements in cryostats comprising, the device comprising any of, or a combination of, the following PC boards, each conditioning a different frequency range: a RC-PC board having a two-stage RC filter in series with a surface-mounted pi-filter; a RF-PC board having a plurality of surface-mounted pi-filters in series, each configured with different low-frequency cutoff frequencies; and a Sapphire-PC board having a sapphire substrate having high heat conductivity at low temperature with thin metal films routed in a meandering fashion.

Abstract: A dynamic acoustic impedance matching device for an acoustic signal transmitted or received in a medium by a transducer includes a particle flow in an acoustic signal path of the transducer. The particle flow has an acoustic impedance between an acoustic impedance of the transducer and an acoustic impedance of the medium.

Abstract: A microelectromechanical (MEMS) microphone includes a MEMS motor and a gain adjustment apparatus. The MEMS motor includes at least a diaphragm and a charge plate and is configured to receive sound energy and transform the sound energy into an electrical signal. The gain adjustment apparatus has an input and an output and is coupled to the MEMS motor. The gain adjustment apparatus is configured to receive the electrical signal from the MEMS motor at the input and adjust the gain of the electrical signal as measured from the output of the gain adjustment apparatus. The amount of gain is selected so as to obtain a favorable sensitivity for the microphone.

Abstract: A circuit assembly for processing an electrical signal of a microphone is provided. The microphone has an inherent impedance. The circuit assembly comprises an impedance circuit, a signal processing unit, a first electrical signal path, and a second electrical signal path. The first electrical signal path is coupleable to a first electrical output of the microphone and is furthermore coupled to a first input of the signal processing unit. The second electrical signal path is coupleable to a second electrical output of the microphone and is furthermore coupled to a second input of the signal processing unit via the impedance circuit. An impedance value of the impedance circuit is selected based on an impedance value of the inherent impedance of the microphone.

Abstract: An ultrasonic piezoelectric transducer device includes a transducer array consisting of an array of vibrating elements, and a base to which the array of vibrating elements in the transducer array are attached. The base include integrated electrical interconnects for carrying driving signals and sensed signals between the vibrating elements and an external control circuit. The base can be an ASIC wafer that includes integrated circuitry for controlling the driving and processing the sensed signals. The interconnects and control circuits in the base fit substantially within an area below the array of multiple vibrating elements.

Abstract: An ultrasonic piezoelectric transducer device includes a transducer array consisting of an array of vibrating elements, and a base to which the array of vibrating elements in the transducer array are attached. The base include integrated electrical interconnects for carrying driving signals and sensed signals between the vibrating elements and an external control circuit. The base can be an ASIC wafer that includes integrated circuitry for controlling the driving and processing the sensed signals. The interconnects and control circuits in the base fit substantially within an area below the array of multiple vibrating elements.

Abstract: A MEMS device includes a MEM-CMOS module having a CMOS chip and a MEMS chip. The MEMS chip includes a port exposed to the environment. The MEMS device further includes a printed circuit board (PCB) with an aperture, wherein the MEMS-CMOS module is directly mounted on the PCB.

Abstract: There is provided a micro electro mechanical system (MEMS) microphone package including: an MEMS microphone chip having an internal space formed therein; a substrate having the MEMS microphone chip mounted thereon; an ASIC chip disposed in the internal space formed within the MEMS microphone chip; and a case bonded to the substrate and having an internal space formed therein in order to accommodate the MEMS microphone chip.

Abstract: Ultrasonic signals are used to transmit sounds from a modulated ultrasonic generator to other locations from which the sounds appear to emanate. In particular, an ultrasonic carrier is modulated with an audio signal and demodulated on passage through the atmosphere. The carrier frequencies are substantially higher than those of prior systems, e.g., at least 60 kHz, and the modulation products thus have frequencies which are well above the audible range of humans; as a result, these signals are likely harmless to individuals who are within the ultrasonic fields of the system. The signals may be steered to moving locations, and various measures are taken to minimize distortion and maximize efficiency.

Abstract: A MEMS microphone assembly includes a MEMS transducer element having a back plate and a diaphragm displaceable relative to the back plate. A bias voltage generator is adapted to provide a DC bias voltage applicable between the diaphragm and the back plate. An amplifier receives an electrical signal from the MEMS transducer element and provides an output signal. The amplifier is adapted to amplify the electrical signal from the MEMS transducer element according to an amplifier gain setting. A processor is adapted to carry out a calibration routine at power-on of the microphone assembly determining information regarding the DC bias voltage and/or the amplifier gain setting.

Abstract: A piezoelectric speaker includes: a piezoelectric vibrator including a piezoelectric body formed of a piezoelectric element and a plate-shaped body which has a larger diameter than the piezoelectric body and which is attached to a surface of the piezoelectric body in a concentric form; and a film-shaped body that is provided around the piezoelectric vibrator so as to elastically hold the piezoelectric vibrator. The film-shaped body includes a coarse and dense portion in a circumferential direction thereof, which has a physically coarse portion which can become a mountain portion or a valley portion or both, and which is disposed so as to correspond to a natural frequency of an in-phase mode in which antinodes and nodes are formed in a concentric form. The piezoelectric vibrator and the film-shaped body form a sound producing body.

Abstract: In accordance with an embodiment, an interface circuit includes a variable voltage bias generator coupled to a transducer, and a measurement circuit coupled to an output of the transducer. The measurement circuit is configured to measure an output amplitude of the transducer. The interface circuit further includes a calibration controller coupled to the bias generator and the measurement circuit, and is configured to set a sensitivity of the transducer and interface circuit during an auto-calibration sequence.

Abstract: In accordance with an embodiment, an interface circuit includes an amplifier configured to be coupled to a transducer, a first bypass circuit coupled to a first voltage reference and the amplifier, a second bypass circuit coupled to the first voltage reference and the amplifier, and a control circuit coupled to the second bypass circuit. The first bypass circuit conducts a current when an input signal amplitude greater than a first threshold is applied to the transducer and the control circuit causes the second bypass circuit to conduct a current for a first time period after the first bypass circuit conducts a current.

Abstract: An alarm sounder, which incorporates a piezo-electric output transducer, can be silently monitored using a variable frequency square wave. An initial frequency, close to the upper limit of human hearing, is coupled to the sounder. The transducer draws very little current at this initial frequency. The frequency of the square wave is systematically reduced, and the current draw is continually monitored. A high current indicates a low impedance type of fault. A low current throughout the frequency range indicates a potential high frequency type of fault.

Abstract: A processing chip for a digital microphone and related input circuit and a digital microphone are described herein. In one aspect, the input circuit for a processing chip of a digital microphone includes: a PMOS transistor, a resistor, a current source, and a low-pass filter. The described processing chip possesses high anti high-frequency interference capabilities and the described input circuit possesses high high-frequency power supply rejection ratio.

Abstract: A MEMS structure and a method for operation a MEMS structure are disclosed. In accordance with an embodiment of the present invention, a MEMS structure comprises a substrate, a backplate, and a membrane comprising a first region and a second region, wherein the first region is configured to sense a signal and the second region is configured to adjust a threshold frequency from a first value to a second value, and wherein the backplate and the membrane are mechanically connected to the substrate.

Abstract: A method for driving a condenser microphone is provided. The condenser microphone comprises a membrane and an electrode constituting a capacity. A polarization voltage is applied between the membrane and the electrode. According to the method, an electrical signal generated by the condenser microphone based on a received acoustic signal causing a deflection of the membrane) is detected, and the polarization voltage is varied in response to the detected electrical signal.

Abstract: A microphone includes a microelectromechanical system (MEMS) circuit and an integrated circuit. The MEMS circuit is configured to convert a voice signal into an electrical signal, and the integrated circuit is coupled to the MEMS circuit and is configured to receive the electrical signal. The integrated circuit and the MEMS circuit receive a clock signal from an external host. The clock signal is effective to cause the MEMS circuit and integrated circuit to operate in full system operation mode during a first time period and in a voice activity mode of operation during a second time period. The voice activity mode has a first power consumption and the full system operation mode has a second power consumption. The first power consumption is less than the second power consumption. The integrated circuit is configured to generate an interrupt upon the detection of voice activity, and send the interrupt to the host.

Abstract: The present solution relates to a device (800) comprising a touch sensitive display (111). The device (800) further comprises a receiving unit (701) configured to receive image data. The device (800) further comprises a processing unit (703) configured to display the image data as a haptic image on the touch sensitive display (111), whereby objects comprised in the haptic image are discernable to a user by sense of touch.

Abstract: Systems and methods for adjusting a bias voltage and gain of the microphone to account for variations in a thickness of a gap between a movable membrane and a stationary backplate in a MEMS microphone due to the manufacturing process. The microphone is exposed to acoustic pressures of a first magnitude and a sensitivity of the microphone is evaluated according to a predetermined sensitivity protocol. The bias voltage of the microphone is adjusted when the microphone does not meet the sensitivity protocol. The microphone is then exposed to acoustic waves of a second magnitude that is greater than the first magnitude and a stability of the microphone is evaluated according to a predetermined stability protocol. The bias voltage and the gain of the microphone are adjusted when the microphone does not meet the stability protocol.

Abstract: A piezoelectric MEMS microphone comprising a multi-layer sensor that includes at least one piezoelectric layer between two electrode layers, with the sensor being dimensioned such that it provides a near maximized ratio of output energy to sensor area, as determined by an optimization parameter that accounts for input pressure, bandwidth, and characteristics of the piezoelectric and electrode materials. The sensor can be formed from single or stacked cantilevered beams separated from each other by a small gap, or can be a stress-relieved diaphragm that is formed by deposition onto a silicon substrate, with the diaphragm then being stress relieved by substantial detachment of the diaphragm from the substrate, and then followed by reattachment of the now stress relieved diaphragm.

Abstract: A condenser microphone includes a condenser microphone unit and a piezoelectric element. The piezoelectric element is disposed so as to generate piezoelectric signals in response to vibration causing the unit to generate vibratory noise signals. The piezoelectric signals are inputted through a low-pass filter and a level adjuster circuit to the unit to drive a diaphragm of the unit. The vibratory noise signals generated by the vibration in the unit are canceled with the piezoelectric signals generated by the piezoelectric element.

Abstract: A low-noise pre-amplifier with an active load element is integrated into a microphone. The microphone has an acoustic sensor coupled to the intrinsic pre-amplifier. A controllable current source is coupled to the intrinsic pre-amplifier and supplies a pre-amplifier bias current. A current source controller is coupled to the current source and controls the amplitude of the pre-amplifier bias current to maintain the intrinsic pre-amplifier at a bias point at which the intrinsic pre-amplifier amplifies microphone signals produced by the acoustic sensor. The intrinsic pre-amplifier may be actively regulated at the pre-determined bias point using negative feedback. Alternatively, the intrinsic pre-amplifier may be set to the pre-determined bias point by sweeping the pre-amplifier bias current for the intrinsic pre-amplifier over a range of currents.

Abstract: An adjustable charge pump system. The system includes a voltage regulator, a clock circuit, a voltage adjustment circuit, and a charge pump. The voltage regulator is configured to receive an input voltage and output a regulated voltage. The clock circuit is coupled to the voltage regulator and receives the regulated voltage. The voltage adjustment circuit is coupled to the voltage regulator and is configured to receive the regulated voltage and to output a driver voltage. The charge pump includes a plurality of stages. The output of the adjustable charge pump system is adjusted by disabling one or more stages of the first stage and the plurality of subsequent stages.

Abstract: The present invention provides a reverse-phase modulating structure of a piezoelectric ceramic speaker, comprising a positioning frame, an acoustic generator and two or more than two flexible units; wherein the acoustic generator comprises a plurality of ceramic layers stacked onto one another to form a ceramic slat, and said flexible units are clamped between an inner edge of the positioning frame and the acoustic generator. Via the pressure exerted onto the acoustic member by the flexible units, the in-phase movement of the acoustic generator can be modulated and the phase conflict of the acoustic generator can be reduced as well as the prevision of the sound quality distortions such that high quality of the ceramic speaker can be enhanced and realized.

Abstract: A piezoelectric speaker includes a cover with a receiving space and a vibrating speaker unit accommodated in the receiving space. The vibrating speaker unit includes a piezoelectric oscillator including an upper surface and an lower surface, a diaphragm disposed on the upper surface of the piezoelectric oscillator, and a vibrating member kept a distance from the lower surface of the piezoelectric oscillator. The piezoelectric oscillator defines a first amplitude capable of driving the diaphragm only and a second amplitude driving both the vibrating member to vibrating with a largest amplitude and the diaphragm to generate sound. The distance is larger than the first amplitude and smaller than the second amplitude.

Abstract: Disclosed is a vibration module for a portable terminal that includes a housing, a magnetic moving part movable in a first direction within the housing; an elastic member supported between the opposite ends of the magnetic moving part and inner walls of the housing, and a solenoid coil provided in the housing. The vibration module is positioned at one end of the moving section by the magnetic force of the magnetic moving part and an object around the magnetic moving part, allowing the vibration module to provide a user with a feeling similar to a click feeling via the acceleration produced at a stopping instant. In addition, when vibrating, the vibration module generates sufficient vibration power through acceleration at the instant of changing moving direction at the ends of the moving section, to provide an alarm function, such as an incoming call notification.

Abstract: A piezoelectric actuator 60 includes a piezoelectric element 10 expanding and contracting according to a state of an electric field, a pedestal 20, a vibration film 30, and a support member. In the vibration mode of the divided vibration occurring in the piezoelectric actuator in a high frequency band, one or more reinforcement members 50 are selectively disposed on an upper surface or a lower surface of the piezoelectric element 10, in a region where a node of divided vibration occurs. With such configurations, the vibration mode can be changed in the piezoelectric element 10. Therefore, in the frequency sound pressure level characteristics, the divided vibration causing hills or valleys (peaks or dips) can be effectively suppressed, thus enabling the achievement of flatness of frequency sound pressure level characteristics and of reproduction of excellent sound.

Abstract: A piezoelectric acoustic transducer achieves both space-saving and high sound quality without increasing the number of parts. In order to achieve this, the transducer includes a piezoelectric element constructed of a piezoelectric material interposed between two surface electrodes and a diaphragm of which at least one principal surface is provided with a print wiring and at least one principal surface is bonded to the piezoelectric element. The diaphragm includes a frame section, a vibrating section which is bonded with the piezoelectric element and which vibrates, and at least one supporting section which connects the frame section and the vibrating section and which supports the vibrating section. Either the frame section or the at least one supporting section includes at least one electrical resistance which is integrally formed to the print wiring and which constructs, in combination with the piezoelectric element, a series-RC circuit.

Abstract: Processing an audio signal is disclosed. The audio signal is received from a sensor coupled to a touch input medium. An indication of an event where the touch input medium has been contacted at a location on the touch input medium is received. The event has been captured as an audio signal component of the received audio signal. At least a portion of the audio signal component is reduced from the audio signal.

Abstract: A driver circuit for a piezoelectric speaker is described, wherein charge is transferred from a charge reservoir to the speaker. In a first embodiment a delta sigma circuit uses a pulse width modulated digital audio signal to control a push-pull circuit to drive the piezoelectric speaker. High frequency harmonics are introduced to the delta sigma drive signals to enhance the low frequency response of the speaker. A charge recovery mechanism recovers charge from the speaker to reduce the frequency of replenishing the charge reservoir and to provide additional drive current for the speaker. In a second embodiment the pulse width modulated signal is used to drive a voltage quadrupling circuit that drives the piezoelectric speaker, wherein the reservoir capacitor is integrated with the capacitors of quadrupling circuit, which provides charge recovery.

Abstract: There is disclosed a microphone, a circuit, and a method. A microphone capsule may include an electret microphone and a field effect transistor (FET). A floating DC voltage source may have a first end connected to a drain terminal of the electret microphone capsule and a second end. A load resistor may be connected between the second end of the floating DC voltage source and a source terminal of the electret microphone capsule. A voltage follower may have an output connected to the source terminal of the electret microphone capsule and the first end of the floating DC voltage source. A coupling capacitor may couple an audio signal from the source terminal of the electret microphone capsule to an input of the voltage follower.

Abstract: Semiconductor structures with high impedances for use in biasing for applying voltage bias to part of a device. The semiconductor structure comprises a continuous structure having a plurality of regions of a first semiconductor type (n type or p type) material arranged alternately with at least one region of the opposite type. The structure may be formed from polysilicon and may also include a plurality of intrinsic regions arranged between the n and p type regions. The structure forms a composite diode and provides a high impedance.

Abstract: A piezoelectric MEMS microphone comprising a multi-layer sensor that includes at least one piezoelectric layer between two electrode layers, with the sensor being dimensioned such that it provides a near maximized ratio of output energy to sensor area, as determined by an optimization parameter that accounts for input pressure, bandwidth, and characteristics of the piezoelectric and electrode materials. The sensor can be formed from single or stacked cantilevered beams separated from each other by a small gap, or can be a stress-relieved diaphragm that is formed by deposition onto a silicon substrate, with the diaphragm then being stress relieved by substantial detachment of the diaphragm from the substrate, and then followed by reattachment of the now stress relieved diaphragm.

Abstract: A system and method for sensing acoustic sounds is provided having at least one directional sensor, each directional sensor including at least two compliant membranes for moving in reaction to an excitation acoustic signal and at least one compliant bridge. Each bridge is coupled to at least a respective first and second membrane of the at least two membranes for moving in response to movement of the membranes it is coupled to for causing movement of the first membrane to be related to movement of the second membrane when either of the first and second membranes moves in response to excitation by the excitation signal. The directional sensor is controllably rotated to locate a source of the excitation signal, including determining a turning angle based on a linear relationship between the directionality information and sound source position described in experimentally calibrated data.

Abstract: A micro-electromechanical (MEMS) based directional sound sensor includes a two sensor wings attached to a surrounding support structure by two legs. The support structure is hollow beneath the sensor wings allowing the sensor wings to vibrate in response to sound excitation. In one embodiment, interdigitated comb finger capacitors attached on the sensor wing edges and the support structure enable an electrostatic (capacitive) readout related to the vibrations of the sensor which allows determination of the sound direction.

Abstract: In order to miniaturize a piezoelectric body module, in which a rhombus-shaped electronic part 4 and a polygonal-shaped electronic part 5 are arranged on a rectangular substrate 2: the rhombus-shaped electronic part 4 is arranged on the substrate 2 such that a side 105 of the substrate 2 and a side 101 of the rhombus-shaped electronic part 4 are parallel to each other; and the polygonal-shaped electronic part 5 is arranged on the substrate 2 such that a side 104 of the rhombus-shaped electronic part 4 and a side 109 of the polygonal-shaped electronic part 5 are parallel to each other.

Abstract: A condenser microphone includes a condenser microphone unit and a piezoelectric element. The piezoelectric element is disposed so as to generate piezoelectric signals in response to vibration causing the unit to generate vibratory noise signals. The piezoelectric signals are inputted through a low-pass filter and a level adjuster circuit to the unit to drive a diaphragm of the unit. The vibratory noise signals generated by the vibration in the unit are canceled with the piezoelectric signals generated by the piezoelectric element.

Abstract: A unidirectional active microphone that includes a diaphragm, coil, and piezoelectric component. An electrical circuit provides amplification to the coil. The piezoelectric component produces unidirectional coupling between coil and diaphragm. The microphone is unidirectional in that the amplification is provided solely to the coil and is not transferred to the diaphragm.

Abstract: An electroacoustic transducer comprises an electric sound conversion section that vibrates a mechanical device based on an electric signal so as to emit a sound wave; and an electromagnetic wave radiation section that generates and emits an electromagnetic wave from the electrical signal.

Abstract: A flat-panel speaker is attached to an exterior surface of a printed circuit board (PCB) housed within a consumer electronic device. Rather than place the flat-panel speaker within a sealed speaker box and then attach the speaker box to the PCB, as is conventional, the present invention attaches the flat-panel speaker to the exterior surface of the PCB without the speaker box. Removing the speaker box allows designers to reduce the dimensions of the device, and to minimize the complexity of the device.