Abstract: A transducer assembly utilizing at least two MEMS transducers is provided, the transducer assembly preferably defining either an omnidirectional or directional microphone. In addition to at least first and second MEMS transducers, the assembly includes a signal processing circuit electrically connected to the MEMS transducers, a plurality of terminal pads electrically connected to the signal processing circuit, and a transducer enclosure housing the first and second MEMS transducers. The MEMS transducers may be electrically connected to the signal processing circuit using either wire bonds or a flip-chip design. The signal processing circuit may be comprised of either a discrete circuit or an integrated circuit. The first and second MEMS transducers may be electrically connected in series or in parallel to the signal processing circuit. The first and second MEMS transducers may be acoustically coupled in series or in parallel.

Abstract: A dual backplate microphone is provided that utilizes either an electret condenser or a MEMS condenser configuration and in which an op-amp IC is electrically connected to both backplates and the conductive layer of the diaphragm.

Abstract: A transducer assembly utilizing at least two MEMS transducers is provided, the transducer assembly preferably defining either an omnidirectional or directional microphone. In addition to at least first and second MEMS transducers, the assembly includes a signal processing circuit electrically connected to the MEMS transducers, a plurality of terminal pads electrically connected to the signal processing circuit, and a transducer enclosure housing the first and second MEMS transducers. The MEMS transducers may be electrically connected to the signal processing circuit using either wire bonds or a flip-chip design. The signal processing circuit may be comprised of either a discrete circuit or an integrated circuit. The first and second MEMS transducers may be electrically connected in series or in parallel to the signal processing circuit. The first and second MEMS transducers may be acoustically coupled in series or in parallel.

Abstract: A surface mountable package for use with an audio transducer is provided. In addition to the audio transducer, the surface mountable package includes a substrate, a cover, and a transducer support frame mounted within, and attached to, the substrate and cover. The support frame includes one or more cavities that, in combination with the audio transducer, substrate and cover, define the front and rear acoustic cavity volumes.

Abstract: An omnidirectional electret condenser microphone element with improved low frequency background ambient acoustical noise rejection is provided. The omnidirectional electret condenser microphone element includes a plurality of passageways in acoustic series that couple at least one acoustic aperture of the microphone element to an acoustic cavity formed within the microphone element. At least one of said plurality of passageways is of a predefined size that is determined to provide the desired response roll-off within a predefined frequency range. In at least one preferred configuration, the roll-off resulting from the plurality of passageways is greater than 2.0 dB between 300 and 100 Hz. In at least one alternate preferred configuration, the roll-off resulting from the plurality of passageways is greater than 3.0 dB between 300 and 100 Hz.

Abstract: A surface mountable package for use with an audio transducer is provided. In addition to the audio transducer, the surface mountable package includes a substrate, a cover, and a transducer support frame mounted within, and attached to, the substrate and cover. The support frame includes one or more cavities that, in combination with the audio transducer, substrate and cover, define the front and rear acoustic cavity volumes.

Abstract: A surface mountable transducer package is provided, the design of which allows a thin package profile to be achieved. An encapsulation layer bonds to a surface of each of the terminal pads and encapsulates a portion of the transducer and at least a portion of the signal processing IC.

Abstract: A transducer package fabrication process is provided, the completed transducer package achieving a thin package profile. The fabrication process utilizes an encapsulation material to eliminate the need for a transducer support substrate, the encapsulation material isolating the terminal pads from one another while holding the transducer and signal processing IC in position.

Abstract: An omnidirectional electret condenser microphone element with improved low frequency background ambient acoustical noise rejection is provided. The omnidirectional electret condenser microphone element includes a plurality of passageways in acoustic series that couple at least one acoustic aperture of the microphone element to an acoustic cavity formed within the microphone element. At least one of said plurality of passageways is of a predefined size that is determined to provide the desired response roll-off within a predefined frequency range. In at least one preferred configuration, the roll-off resulting from the plurality of passageways is greater than 2.0 dB between 300 and 100 Hz. In at least one alternate preferred configuration, the roll-off resulting from the plurality of passageways is greater than 3.0 dB between 300 and 100 Hz.

Abstract: A telephone handset that includes both a speaker and a secondary flux coil is provided. The secondary flux coil provides improved inductive coupling between the handset and a hearing aid. Due to the wiring configuration of the handset, the speaker and the secondary flux coil can be independently filtered, thus providing means for independently optimizing the performance of both the speaker and the secondary flux coil. Suitable filters include both passive circuits and digital signal processors.

Abstract: A telephone handset that includes both a speaker and a secondary flux coil is provided. The secondary flux coil provides improved inductive coupling between the handset and a hearing aid. Due to the wiring configuration of the handset, the speaker and the secondary flux coil can be independently filtered, thus providing means for independently optimizing the performance of both the speaker and the secondary flux coil. Suitable filters include both passive circuits and digital signal processors.

Abstract: A direction finder arrangement advantageously employs a plurality of transducers to derive a plurality of predetermined polar directivity patterns each of which has a predetermined spatial orientation pointing in a predetermined fixed direction relative to each of the other polar directivity patterns. The polar directivity patterns detect a plurality of amplitude values of a propagating wave approaching at different angles relative to the plurality of spatially oriented polar directivity patterns. Then, the detected wave amplitude values are processed to determine an estimate of a direction toward the source of the arriving wave. More specifically, the detected amplitude values are processed to obtain an estimate of the directional orientation of a hypothetical polar directivity pattern pointing toward the source of the arriving wave.

Abstract: A moving-armature transducer assembly suitable for use as an alerter in a portable telephone. The assembly includes a transducer housed in an enclosure including first and second acoustical chambers. A first sound emitted from a front hole on a front side of the transducer is propagated through the first acoustical chamber and emitted from a first port of the assembly. A second sound emitted from a rear hole on a rear side of the transducer is phase-shifted by the second acoustical chamber acting in combination with a second port or ports on the assembly to have a phase coinciding with the phase of the first sound. The second sound then combines with the first sound, reinforcing the first sound and producing a combined sound having an increased level and bandwidth.

Abstract: A monolithic second order gradient (SOG) microphone structure employs acoustic transmission lines wherein the acoustic phase delay along each of the acoustic transmission lines is in direct proportion to the length of each of the acoustic transmission lines and, where this is effected by the use of an acoustic impedance element placed within each acoustic transmission line that has an acoustic impedance related to the acoustic impedance of the associated acoustic transmission line. In one embodiment, the acoustic impedance element has a specific acoustic impedance substantially matched to the specific acoustic characteristic resistance of the acoustic transmission line. Various embodiments may utilize acoustic or electrical subtraction of the signals in the acoustic transmission lines to realize the desired directional sound pickup.

Abstract: An improved Broadside SOG microphone assembly is realized by employing a microphone assembly having at least three ports arranged in a non-colinear fashion with the at least three ports defining and being in a "gradient" plane and with both outer adjacent differential pair of ports aligned in a direction substantially toward a prospective talker's lips. Thus, the inner port(s) is always closer to the prospective talker's lips. Each outer differential pair of ports forms a dipole which yields a high spatial gradient and, hence, higher speech sensitivity since they are pointed substantially toward the prospective talker's lips. Just as important, as the prospective talker's lip position relative to the microphone varies, this alignment of each outer differential pair of ports will result in the least change in the dipole sensitivity and, therefore, the lowest Broadside SOG microphone position sensitivity.

Abstract: An electroacoustic transducer in accordance with the present invention comprises a perforated backplate having a plurality of upstanding parallel ribs between which conductive surfaces are situated. The conductive surfaces are electrically interconnected with one another and with a contact surface on a relieved shoulder at one end of the backplate. This shoulder is engaged by a bifurcated contact spring that (1) electrically connects the conductive surfaces to the input of an integrated preamplifier circuit deposited on a substrate and (2) holds the substrate in place on the underside of the backplate.An electret diaphragm having a metallized surface is tensioned across the ribs of the backplate with the metallized surface facing away from the backplate, and while so tensioned, the ends of the diaphragm are clamped against the backplate by a conductive intermediate member that makes electrical contact with the diaphragm.