Abstract: A digital microphone includes built-in self-test features. The features may include capability to apply different bias voltages to a MEMS capacitor sensor of the digital microphone, simulating application of different sound pressures to the digital microphone. The features may also include a digital oscillator, for applying a test signal to an analog front end of the microphone.

Abstract: According to one embodiment, a strain and pressure sensing device includes a semiconductor circuit unit and a sensing unit. The semiconductor circuit unit includes a semiconductor substrate and a transistor. The transistor is provided on a semiconductor substrate. The sensing unit is provided on the semiconductor circuit unit, and has space and non-space portions. The non-space portion is juxtaposed with the space portion. The sensing unit further includes a movable beam, a strain sensing element unit, and first and second buried interconnects. The movable beam has fixed and movable portions, and includes first and second interconnect layers. The fixed portion is fixed to the non-space portion. The movable portion is separated from the transistor and extends from the fixed portion into the space portion. The strain sensing element unit is fixed to the movable portion. The first and second buried interconnects are provided in the non-space portion.

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 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: The present invention relates to a microphone assembly comprising a microphone assembly casing having a sound inlet port and a transducer for receiving acoustic waves through the sound inlet port. The transducer converts the received acoustic waves to analog audio signals. The assembly according to the present invention further comprises an electronic circuit positioned within the microphone assembly casing, said electronic circuit comprising a pre-amplifier and an analog-to-digital converter preferably in form of a sigma-delta modulator so as to convert amplified analog audio signals to digital audio signals.

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: According to one embodiment, a strain and pressure sensing device includes a semiconductor circuit unit and a sensing unit. The semiconductor circuit unit includes a semiconductor substrate and a transistor. The transistor is provided on a semiconductor substrate. The sensing unit is provided on the semiconductor circuit unit, and has space and non-space portions. The non-space portion is juxtaposed with the space portion. The sensing unit further includes a movable beam, a strain sensing element unit, and first and second buried interconnects. The movable beam has fixed and movable portions, and includes first and second interconnect layers. The fixed portion is fixed to the non-space portion. The movable portion is separated from the transistor and extends from the fixed portion into the space portion. The strain sensing element unit is fixed to the movable portion. The first and second buried interconnects are provided in the non-space portion.

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: The invention provides an integrated circuit. The integrated circuit receives a first signal from a microphone via a first node. In one embodiment, the integrated circuit comprises a biasing circuit and a buffering circuit. The biasing circuit is coupled between the first node and a second node, drives the microphone with a first voltage source, and filters the first signal to generate a second signal at the second node. In one embodiment, the biasing circuit comprises a first resistor, a first capacitor, and a load element. The first resistor is coupled between the first voltage source and the first node. The first capacitor is coupled between the first node and the second node. The load element is coupled between the second node and a second voltage source. The buffering circuit is coupled between the second node and a third node and buffers the second signal to generate a third signal at the third node.

Abstract: A mobile terminal having a dual display unit, a dual speaker and a dual microphone, and a method of controlling the dual speaker and the dual microphone thereof are provided. The method of controlling a dual speaker and a dual microphone of a mobile terminal having a dual display unit including a first body having a first display unit and first speaker on a front surface and a second display unit and second speaker on a rear surface, a second body having a first and a second microphone, and a hinge module for rotatably connecting the first body and the second body, includes determining which of the first and second display units is activated; activating, if the first display unit is activated, the first speaker; and activating, if the second display unit is activated, the second speaker.

Abstract: A microphone including a connector with a plurality of electrical contacts. The microphone interfaces with a computer system via a digital bus. The microphone can transmit data to the computer system via the connector that is related to at least one of the following: the microphone manufacturer, the microphone manufacture date, the microphone model number, the microphone serial number, the microphone frequency response, whether the microphone uses phantom power, the desired pre-amplifier gain, and the microphone dynamic response.

Abstract: A security system and methodology are provided employing a process that determines whether to use an image and/or other inputs received from at least one remote input node. In one illustrative embodiment, the invention comprises a system and method for using image input in conjunction with wireless transmission to increase personal safety.

Abstract: A microphone preamplifier, comprising a differential input (102) stage with a first and a second input terminal and an output stage with an output terminal; where the microphone preamplifier is integrated on a semiconductor substrate. A feedback circuit, with a low-pass frequency transfer function (103), is coupled between the output terminal and the first input terminal and integrated on the semiconductor substrate. The second input terminal provides an input for a microphone signal (105). Thereby a very compact (with respect to consumed area of the semiconductor substrate), low noise preamplifier is provided.

Abstract: An integrated circuit (102) configured to provide a microphone output signal, comprising: a preamplifier (108) coupled to receive an input signal, generated by a first microphone member that is movable relative to a second microphone member; and a voltage pump (104) to provide a bias voltage to either microphone member.

Abstract: A system and method for assisting listening wherein an integrated circuit selects one or more audio sources from among a plurality audio sources to be presented to a signal processing circuit. Selection of the audio source can be automatically executed in response to detection of an external magnetic field, such as from a telephone handset, or manually controlled by a user input.

Abstract: A microphone assembly comprising a housing, the housing including an upper lip, a silicon backplate having a top portion, a bottom portion, an annular side portion, a silicon spacer integrally formed with the backplate and comprising at least one protrusion extending from and integral to the top portion of the silicon backplate, the spacer further comprising an insulating layer, such as silicon dioxide or a fluoropolymer. A plurality of openings extend from the top portion of the backplate to the bottom portion of the backplate. A single diaphragm, comprised of metallized polymer film, acts as both a protective environmental barrier and a sensing electrode of a capacitive electroacoustic sensing transducer. A metal ring is positioned against the upper lip of the metal housing. The diaphragm is adhesively affixed to the ring, and the ring, in cooperation with the upper lip and a spring, secure the diaphragm against the insulating layer of the spacer.

Abstract: A microphone is provided with a simple structure by which a lead wire is not required to detect displacement of a vibrated film. The microphone is equipped with a vibrated film 2 to receive sonic waves on either surface and to receive electro-magnetic waves on other surface, a device 4 to receive and transmit the electro-magnetic waves reflected by the vibrated film, a counter to count pulses from the device to receive and transmit electro-magnetic waves, a processing logic 5 to count the pulses output from the counter. Displacement of the vibrated film is converted into electric signals by counting the processing logic the frequency and amplitude of the electro-magnetic waves reflected by the vibrated film 2.

Abstract: A digital microphone has a transducer for generating an analog signal representing an acoustic signal, and a single bit sigma-delta modulator analog-to-digital converter of order greater than one for generating a digital output signal from said analog signal in the form of a sigma-delta modulated bit stream at an oversampled rate. The digital microphone avoids the need to include digital decimation and filtering circuits within the microphone housing and thus lends itself better to integration technologies.

Abstract: A microphone apparatus including a vacuum-tube amplifier amplifying an electric signal converted from an acoustic signal includes a thermo-ionic cooling element having two surfaces, in which a first surface is in contact with the vacuum-tube amplifier for absorbing the heat generated from the vacuum-tube amplifier and the absorbed heat is radiated to the exterior from the second surface.

Abstract: The disclosure relates to devices for the measurement of signals in the field of wideband phenomena. More precisely, a device is disclosed for the processing of electrical signals coming from a derivative type of sensor designed to measure an electrical or magnetic field, currents, surface charges or other derivative variables, said processing including the computation of the primitive of the part of said signal having a spectral frequency higher than a low frequency f.sub.1, the device comprising:means for the electronic integration of said signal, from a frequency f.sub.2 higher than said low frequency f.sub.1 ;compensation means amplifying and integrating said signal between the frequencies f.sub.1 and f.sub.2. FIG. 2 .

Abstract: A loudspeaker driver has its front surface adjacent one end of a low loss acoustic waveguide and its rear surface adjacent to one end of a second acoustic waveguide that is one third the length of the first. The other openings of the waveguides face air and couple acoustical energy substantially uniformly over a relatively broad range of frequencies extenting into the bass frequency region. An equalizer includes a notch filter so that the frequency response of the equalizer below a bass cutoff frequency is sufficiently low to prevent audible distortion.

Abstract: A microphone designed for use on location provided with amplification to produce a signal output level suitable for use on conventional studio cables and utilizing the Phantom power available on such studio cables, the microphone having a light emitting diode responsive to elevation of the potential of the Phantom power on the cable, but not the normal potential thereof, to indicate the presence of a live microphone, the microphone also being provided with a backup battery for use in the event Phantom power is not available, and the microphone being provided with a free running multivibrator coupled to the light emitting diode and having a repetition rate proportional to the potential of the backup battery to give an indication of battery voltage.

Abstract: A system for a telephone answering machine for recording new announcements on the announcement tape, for dictating notes or other material on the message tape, and for reproducing messages recorded on the message tape, all by means of a single transducer, so that the need for a separate microphone for dictation purposes and for recording new announcements on the announcement tape is obviated.