Abstract: A hearing aid of the type which is worn behind the ear has a battery compartment and a volume control knob at its lower end. The compartment and knob are at right angles to the longitudinal axis of the device.

Abstract: A headband for a headset has separate coarse and fine adjustment features. The adjustments may be to the axial distance between at least one earpiece element and a side support. Such adjustment to the axial distance varies the pressure exerted on the head of the user. The present fine adjustment feature may be used while the headset is being worn, thereby permitting a user to optimize the amount of pressure between the contending criteria of comfort and keeping the headset in place on the user's head.

Abstract: A speaker unit having a pair of voice coils each wound around a common coil bobbin and a first magnet for driving one coil of the pair of voice coils. A second magnet is provided for suppressing flux leakage of the first magnet and driving one coil of the pair of voice coils.

Abstract: A simple combination handset and headset device includes an elongated, preferably flexible body with a mouthpiece at one end thereof and an earpiece at the other end thereof, and a tubular arm pivotally connected to the mouthpiece for rotation between handset and headset positions, whereby, when the arm lies against the body, the combination can be used in the same manner as a conventional handset, and when the body is extended and the arm rotated, the combination can be used as a headset.

Abstract: An improved telephone set of the type including a telephone body and a handset adapted to be placed on the former. The telephone body has a pair of engagement blocks incorporated therein of which part is projected outwardly of the telephone body and they are fitted into engagement recesses on the handset whereby the latter is firmly placed on the telephone body. At least the one engagement block has an engagement face which is adapted to come in contact with the engagement portion in the corresponding engagement recess. Thus, the handset is reliably held on the telephone body.

Abstract: A dual cavity pressure microphone comprising a microphone housing and an oscillating element mounted in or on said housing. The oscillating element including a membrane which is in principle only sensitive to a sound field on one side, the second side forming part of a closed cavity in the microphone housing, said cavity being connected to the ambient atmosphere through a narrow pressure equalizing channel. The microphone comprises an additional cavity representing an additional acoustic capacitance and an additional pressure equalizing channel located in series therewith and representing an additional acoustic resistance, the second capacitance and the second resistane being located in series with the capacitance and resistance, respectively, of the first cavity and the first channel in such a manner, that the pressure equalization of the microphone is also effected through the additional pressure equalizing channel and the additional cavity.

Abstract: Assembly of handsets is accomplished without the use of mechanical fastenings. Energy directors are provided at the peripheral edges of one of the two housings forming a handset, and the two housings are united by sonic welding. Severe damage can be caused to transducers mounted in the handset by sonic welding, but the use of energy directors directs the sonic energy around the transducers, avoiding damage. The transducers can be held in place by heatstaking positioning members. A rigid assembly which is readily amenable to automated assembly is provided.

Abstract: A hearing aid which can be built into a frame, such as eyeglasses, to be worn by a hearing-impaired person has a first microphone arrangement having a directional reception pattern, and a second microphone arrangement for sound locating. The second microphone arrangement includes a first locating microphone disposed in the region of one ear of the hearing-impaired person, and a second locating microphone disposed in the region of the other ear. The signal from both locating microphones are mixed by a low-pass filter with the signal from the microphone arrangement having a directional reception pattern, and the output of the mixing operation is supplied in common to both ears of the hearing-impaired person.

Abstract: A lock is provided for a pushbutton phone, whereby when a correct key is inserted to rotate a cylinder an actuating member is forced to rotate therewith so that two arms of the actuating member urge two sliding plates to slide, causing the projections of the sliding plates to bear against the arms of a confining member and enabling teeth on the arms of the confining member to lock up the pushbuttons. When the correct key is inserted to rotate the cylinder back to its original position, the projections of the sliding plates separate from the arms of the confining member and the arms then go back to their original states to release the pushbuttons.

Abstract: Earphones especially adapted for use in audiometry have electroacoustical transducer elements located at a distance from the ear and incorporate coupling paths and chambers so arranged as to eliminate undesirable resonances and to obtain a smooth and accurate frequency response characteristic.

Abstract: An attachment for a telephone handset includes a portion which engages a groove in the handset and which may be rotated along the groove. A lens is mounted in a frame rotatably attached to the portion which engages the handset to allow the lens to be oriented for left or right handed use. A connection between the lens frame and the portion engaging in the handset includes a socket which receives flexible projections for holding the frame in any of several desired orientations. In use, a lens is positioned to provide optical assistance for an operator while simultaneously talking on the telephone.

Abstract: An earpiece comprises a suction cup sensor, a preamplifier, a potentiometer for varying the gain of the amplifier, a pass band filter and electronic means enabling the user to adjust the central frequency and/or the width of the pass band of the filter. One application of the invention is the construction of self-contained and individualized telephone handsets or headphones which may be connected without any wire connection on any telephone set.

Abstract: The disklike diaphragm is made up of an essentially conical plastic film provided with vacuum-formed supporting members which extend up to the disklike radiating layer.

Abstract: At least one rotary vane in a tube is driven by a motor in response to an audio signal, causing production of sound through at least one opening in the tube.

Abstract: A diaphragm for an acoustical transducer comprises a support and a separate cover for the support. The support is constructed from a relatively more rigid material having the desired physical characteristics of mass and stiffness for the transducer. The cover comprises a light weight, relatively less rigid, and pliable sheet of material. The cover is attached to the support, illustratively by an adhesive, to form the diaphragm.

Abstract: A noise elimination circuit, especially for a hearing aid, which removes all sound below a predetermined level and transmits a compressed sound range for all sounds above a predetermined level. The circuit uses a field effect transistor as a voltage variable resistor to transmit a signal when the sound signal is being compressed or is over a predetermined level and block the signal when the sound signal is not being compressed or is below the predetermined level. The field effect transistor drain to source resistance is varied by transmitting a signal indicative of the compression or signal level to the gate of the transistor, such that the gate voltage is higher than the source voltage when signal transfer is desired and the gate voltage is less than the source voltage when no signal transfer is desired. A switch is provided to defeat the noise elimination circuitry.

Abstract: A contoured shoulder reset for use with a telephone to provide a more comfortable support and including an adjustable member which allows the shoulder rest to fit the shoulder more securely thereby making the unit more stable when in use as in intended.

Abstract: A speaker system having a magnet and voice coil are mounted within a dome-shaped enclosure in such a way as to be capable of transmitting sonic vibrations and audio waves through a liquid medium or solid structure, the dome-shaped enclosure cooperating with the magnet and voice coil in such a way as to greatly enhance the waves and sonic vibrations generated to the other medium or structure.

Abstract: A narrow directional microphone comprising a microphone unit and an interference tube with one end covering a forward audio terminal of the microphone. The interference tube has a plurality of first openings spaced from one another axially on the tube for providing acoustic resistance. The interference tube has a plurality of second openings spaced circumferentially from the first openings about the interference tube with a diaphragm secured to the interference tube for covering the second openings.

Abstract: A microphone comprising a double membrane condenser unit and an amplifier circuit is connected to a power supply. Signals from the two membranes of the unit are fed to each one amplifier and to each one impedance transformer and are delivered through a signal wire to a power supply unit having phantom power supply. In the power supply unit, the signals are added or subtracted in order to give a continuously variable directional characteristic of a round or eight characteristic and are added or subtracted in different proportions by means of a potentiometer in order to give different degrees of a cardioid characteristic. The microphone can also be used as a stereo microphone by assigning the two signals to the right and the left channel, respectively. For balanced signals an inverting buffer is used and a second impedance transformer.