Abstract: In a speech prosthesis, a direct radiator speaker, a rubber membrane over a speaker for sealing against liquid and food, and an O-ring seal for a battery compartment.

Abstract: A method and apparatus for continuously measuring and indicating the variations of the intensity of an electric signal, such as a signal to be recorded on a tape recorder, which provides measuring to take place at successive measuring periods in such a manner that a measured result is yielded representing the maximum value of the signal intensity. The signal intensity is measured during consecutive measuring periods and registered. The indicator has the ability to maintain the read-out of a maximum value, read during a measuring period, during a following hold period, whereby the measuring periods provided have a duration being an order of size less than the time of reaction of the human eye. The system stores the maximum intensity values being detected during each of a series of consecutive measuring periods, and provides hold periods having substantially longer durations by being an order of size longer than the time of reaction of the human eye.

Abstract: Deleterious effects of high capacitance in large area raster scanner image tubes, especially when employed in video cameras, can be overcome by employing the following features: (1) a plurality of transparent stripe signal electrodes; (2) a unique, multiple layer, solid state structure designed to provide a Displaced Electron Layer-Sensor-Target for imaging (hereinafter DELST), with and without; (3) photoconductive gain in the DELST structure; and (4) with and without intensifier gain in the DELST structure, the proper combination of these four features makes possible the construction of video sensor devices of extraordinarily large capacitance, having rasters generated by "low or high" velocity scanning electron beams, or a laser scanning ray. The invention provides a generic approach for the selection of features and their combination with the type of scanner best suited to any one application.

Abstract: A microphone holder for surveillance work and adapted to support a microphone in a concealed position when the holder is taped to the upper torso of a surveillance agent and to avoid clothing rustle and bulges resulting from the normal wear of the holder. The holder is of a flexible rubber material capable of moving with the wearer to permit comfortable use and avoid detection by persons under surveillance. The holder has an upper surface of a generally convex shape and a lower surface which is nearly flat but slightly concave. The upper surface is provided with a recess for the retention of a small microphone that can be un-encased and recessed below the upper surface to avoid clothing rustle. Microphone leads are kept below the upper surface in a groove to further avoid a detectable impression through the clothing of a wearer. Recording means which may include transmitting means is typically located elsewhere on the wearer.

Abstract: A compact video camera which is operable at variable shutter speeds to capture high speed events which may be recorded and played back in slow motion for scene analysis. The video camera includes an image sensor, a variable diaphragm and a variable speed shutter. The variable diaphragm and variable speed shutter are controlled automatically to maintain constant the peak to peak signal level of the video signal produced by the image sensor so that the highest shutter speed is always maintained as scene brightness changes.

Abstract: A compact video camera which is operable at continuously variable shutter speeds to capture high speed events which may be recorded and played back in slow motion for scene analysis. The video camera includes an image sensor, a zoom lens, and a rotating shutter which is continuously adjustable to different shutter speeds. The camera components are dimensioned and configured in a compact design for easy-to-use hand-held operation. The shutter includes a pair of rotating shutter discs having openings which are selectively adjustable relative to each other to vary the interval during which the imager sensor is exposed to a scene projected onto it by the zoom lens. The shutter discs are mounted on respective first and second holow shafts. The first shaft is rotatably and slidably mounted on a portion of the second shaft by a linkage.

Abstract: A compact video camera which is operable at continuously variable shutter speeds to capture high speed events which may be recorded and played back in slow motion for scene analysis. The video camera includes an image sensor, a zoom lens, and a rotating shutter which is continuously adjustable to different shutter speeds. The camera components are dimensioned and configured in a compact design for easy-to-use hand-held operation. The shutter includes a pair of rotating shutter discs having openings which are selectively adjustable relative to each other to vary the interval during which the imager sensor is exposed to a scene projected onto it by the zoom lens. The shutter discs are mounted on a pair of spaced, hollow shafts. Adjustment of the relative rotational position of the two discs to control the size of the relative shutter opening is effected by a push rod linked to and slidably mounted within the hollow shafts.

Abstract: An automatic sound field correcting system with graphic equalizer means to be provided in an audio signal supply line. A test signal such as a pink noise is radiated in the listening space and detected at a predetermined listening point to determine the detection frequency characteristic of the test signal, thereby to adjust the frequency characteristic of the graphic equalizer means. Thereafter, the frequency characteristic of the graphic equalized means is made equal to different band-pass filter characteristics, one after another, and each time the equalization is effected, the detected test signal is obtained through the grapic equalizer means for determination of the detected frequency characteristic of the test signal.

Abstract: The invention relates to electroacoustic transducers and more particularly to microphones in which the conversion of an acoustic vibration into an electric voltage is provided by a piezoelectric diaphragm. The purpose of the invention is to allow transducers to be formed by mass production methods with a minimum of parts for providing the functions of embedment of the diaphragm, connections, screening, acoustic filtering and protection against damp and dust.

Abstract: A hand held housing encloses a battery powered sound generator from which an audible voice simulating tone is transmitted through a tube when a push button switch is depressed also causing illumination of an indicator lamp. The tube is displaceable relative to the housing between extended and retracted positions. In the extended position, the tube may be inserted into the mouth.

Abstract: A silicon micro-transmitter chip is housed within top and bottom closures snap-fitted together by legs and catches on the two closures. The chip is mounted between two acoustic cavities in the closures by a plate part of a configured metal sheet having other strip parts extending through grooves in the bottom closure to its outside where the strips are bent to provide arms for surface mounting the entire device on a printed wiring board. The sheet serves both as a continuous strap for effecting such surface mounting and as an electrode for connecting a terminal of the chip to ground. Other terminals of the chip are connectable to the board by flat leads passing through other grooves in the bottom closure to its outside where they are bent for surface mounting purposes. The housing formed by the two closures includes an adhesive impregnated gasket for providing an acoustic seal between the two cavities as to which the air pressures therein are equalized by a vent hole in the plate.

Abstract: An active noise control system reduces cabin noise levels for a propeller or propfan aircraft due to the propeller noise signature by making the output from a secondary noise source identical in amplitude but opposite in phase to the propeller noise signature.

Abstract: A sound masking apparatus especially useful for setting background noise levels in discrete zones includes a signal source, power amplifier, programmable attenuator and remote control. The remote control is a short range radio transmitter that sends a series of pulses that are decoded to control the attenuator. The attenuator selects among discrete possible volume levels using serially-connected analog multiplexers, the multiplexer-selected lines connecting the signal to a desired part of a resistor network defining voltage dividers. The short range radio control makes a single remote controller operable to control volume levels in any zone of a multiple zone installation without direct access to the signal source, whereby the user can change volume levels in small increments to accomodate changing conditions or preferences and to slowly bring sound masking units to full volume levels.

Abstract: An apparatus is disclosed for providing automatic exposure/focus control in a solid state video camera by converting the image information from a solid state image sensor to a digital representation and using the least significant bits of the digital representation for focus detection and the most significant bits for exposure measurement.

Abstract: An inverse control system is disclosed, which comprises FIR filters provided between transmitting elements at n (n=2, 3, . . . ) input points of a linear FIR system and a common signal source, for an inverse control such as to provide desired impulse responses between the signal source and m (n>m) output points of the linear FIR system. A j-th (j=1, 2, . . . , n) one of the FIR filters has a number L.sub.j of taps which satisfies the relationships represented by ##EQU1## for all i=1, 2, . . . , m and j=1, 2 . . . , n where w.sub.ij is the number of discrete signals representing the impulse response g.sub.ij (k) between the j-th output point and i-output point and P.sub.i is the number of discrete signals representing the desired impulse response r.sub.i (k) between the signal source and i-th output point. The j-th FIR filters has a filter coefficient h.sub.j (k) satisfying the relationship ##EQU2## where .circle.* is a discrete convolution.

Abstract: The invention relates to a fading arrangement in electrical reproduction apparatus, for fading the signals supplied to two reproduction units by a signal source, comprising a variable resistor whose resistance track co-operates with wiper means which, when moved along said track, connect a fading resistance which decreases from the maximum value to the minimum value in series with one reproduction unit and a fading resistance which increases from the minimum value to the maximum value in series with the other reproduction unit. Additional variable resistors (R.sub.Z) are arranged in parallel with the reproduction units (R.sub.L1, R.sub.i1 +R.sub.L1 ; R.sub.L2, R.sub.i2 +R.sub.L2). During the common movement of all the wiper means the additional wiper means vary the resistance values of the additional resistors (R.sub.2, 100 R.sub.2) oppositely, in such a way that the resistance value of the additional resistor (R.sub.

Abstract: The top surface (1a) of the TV camera has a tower block (5, 6) secured thereto including, for example, a "camera ON" or "red light" indicator.

Abstract: An active acoustic attenuation system is provided that actively models direct and feedback paths as well as characteristics of the secondary cancelling sound source and the error path on an on-line basis. The primary model uses a recursive least mean squares RLMS algorithm that is excited by the input acoustic noise and uses the residual acoustic noise as an error signal. The secondary sound source or cancelling speaker and the error path are modeled by a second algorithm, particularly an LMS algorithm, that uses an additional auxiliary low level, random, uncorrelated noise source as an input signal. The resulting overall system provides excellent attenuation of narrow band and broad band noise over a relatively wide frequency range on a completely adaptive basis without directional transducers.

Abstract: An apparatus and a method for reestablishing previously established settings on the controls of an audio mixer having at least one input channel and at least one output channel. The method includes the steps of transmitting a first test signal through the at least one input channel; measuring and recording this first test signal during a first period of time at at least one output channel; transmitting a second test signal, substantially identical to the first test signal, through the at least one input channel during a second period of time; comparing this second test signal at the at least one output during the second period of time with the recorded first test signal; and altering the settings on the controls of the audio mixer in the event that the recorded first test signal is different from the second test signal of the at least one output.

Abstract: An active acoustic attenuation system (2) is provided for attenuating an undesirable output acoustic wave by introducing a cancelling acoustic wave from an omnidirectional speaker (14) at the output (8), and for adaptively compensating for feedback from the speaker (14) to the input (6) for both broad band and narrow band acoustic waves, without pre-training. The feedback path (20) is modeled with a single filter model (40) adaptively modeling the acoustic system (4) on-line without dedicated off-line pre-training, and also adaptively modeling the feedback path (20) from the speaker (14) to the input microphone (10) on-line for both broad band and narrow band acoustic waves without dedicated off-line pre-training, and outputting a correction signal to the speaker (14) to introduce a cancelling acoustic wave.