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 ...

The present invention relates in general to ear muffs and in particular to an ear muff for headphones for portable radios and cassette players and the like, which may be easily removed or exchanged. The ear muff is constructed with a support cup that is covered by fabric, wool or other material which engages, and at least partially surrounds the ear of the wearer to keep it warm in cold weather. The band or strap for the headphone speaker is captured by two overlapping flaps that extend over the...

A photofliudic audio receiver for producing sound directly from light modulated at audio frequencies and amplifying the sound to deliver uniform frequency response over a wide audio frequency range, utilizing only fluidic and thermal devices. It includes a photoacoustic cell for converting the modulated light signal to an acoustic signal, and at least one laminar proportional amplifier (LPA) for amplifying the acoustic signal to provide the sound output of the receiver. Each LPA has a rising fre...

An electroacoustic converter with a closed-off resonance chamber, e.g. a microphone, including frame (1) carrying an electrode (2) and a diaphragm (3) connected by a connecting member (5) to an amplifier. A band (17) of plastically deformable material is sealingly attached to the frame via a weld joint (15) for providing good bass reproduction. The sensitivity of the microphone, which depends on the volume of the resonance chamber, is adjusted to the desired value by forming a depression (16) in...

A speaker system comprises a plurality of serially connected, angularly disposed hollow tubes having a total mean axial length of one-quarter wavelength of the desired lowest frequency response of the speaker system, the speaker system providing, with a single small speaker, the entire frequency range normally provided from a woofer, a midrange and a tweeter while eliminating the phase distortion and the phase problems resulting from dividing networks.

An improved headset of the type including a headband having two ends provided with sliding portions, wherein a pair of adjusting pieces are slidably received through the sliding portions to permit adjusting the height of the adjusting pieces with respect to the headband. The lower end of each adjusting piece is provided with a seat having a connecting member formed on the bottom thereof. A pair of main bodies, each body including a speaker and an ear cushion, are pivotally connected to the conne...

A dynamic speaker device having a small-sized vibrating plate for reproducing a high frequency sound is further provided with an additional coil in the vicinity of the magnet assembly of the speaker. The additional coil is mounted on a comparatively heavy vibrating element which is supported by a spring plate. The additional coil and the vibrating element vibrates to reproduce lower frequency sound and vibration in response to audio signal supplied to the additional coil.

To provide for better fitting and pleasing out appearance of a hearing aid having an element introducible into the ear canal of a user, and an externally accessible housing which retains electronic components, a battery, and ON/OFF switch and volume control elements, the housing is formed in spherical or, rather, truncated-spherical shape, removably fitted on a fitting element introduced into the ear canal. This spherical shape is less obtrusive than others, and may be formed similar to costume ...

Under the condition where a plurality of background noise sources exists, there are arranged a first receiver, primarily receiving desired voice, and a plurality of second receivers each primarily receiving noise from a corresponding noise source. Filter coefficients of equivalent noise-producing filters, each having a frequency transmission characteristic equivalent to that of transmission path from its corresponding noise source to the first receiver, are estimated based upon mutual-correlatio...

A sound-wave receiving applicance comprises a resonance panel and a crystal type piezoelectric microphone responsive to oscillations generated by the soundwaves, said microphone being adapted for connection to an amplifier. The crystal of the microphone is subjected, between two pole members, to a mechanical initial pressure to increase the pressure sensitivity of the microphone relative to the resonance panel. The receiving applicance preferably has means for manual adjustment of the initial pr...