Abstract: A circuit for use in programmable hearing aids is programmed by inputting digital pulses along two input lines. The programmed information is stored in ring counters and then registered in EEPROMS. A multiplexer (itself a ring counter) selects the ring counter which will be incremented by pulses input to one of the input lines.

Abstract: An earwax-protective device having a yoke joined with an auditory passage portion of a hearing aid which makes it possible to easily remove accumulations of earwax without damaging sensitive electrical components in the hearing aid.

Abstract: In a preferred embodiment, a speaker system within a closed wooden cabinet in which the speaker is suspended in closed cell foam within a cabinet speaker circular-port, devoid of rigid attachment of the foam and of the speaker to the cabinet, the closed-cell foam being mounted in an open-ended slot between flanges mounted on the speaker cabinet, and the speaker magnet being supported by a resilient gasket mounted on the cabinet by a gasket-support structure, and a rear port being closed by an inner non-porous membrane and an outer porous fabric membrane having foam therebetween, mounted within a membrane-support frame that is suspended within open cell foam suspended within the rear port devoid of rigid attachment to the cabinet, supported between inner and outer flanges mounted on the cabinet, the cabinet being devoid of open ports.

Abstract: A bass reflex type speaker system has a duct for transmitting sound waves. The duct is formed with a plurality of sound paths, and each of the sound paths has a unique length such that respective differences in the lengths of the sound paths cause destructive interference at particular frequencies. The interference occurs at a wavelength or wavelengths corresponding to the particular frequency or frequencies at which a local relative peak in sound level occurs due to leaking sound.

Abstract: A dual diverging manifold loudspeaker system includes a generally cubically-shaped outer horn housing and an inner dome-like cap member for encapsulating therebetween a compression driver assembly. The loudspeaker system includes a back plate member which is secured adjacent to the rear end of the housing. The back plate member includes a first diverter member for diverting a planar sound wavefront into two diverging sound wavefronts, a pair of second diverter members for splitting the two diverging sound wavefronts into four separate planar wavefronts, and reflector members for deflecting forwardly the four separate planar wavefronts toward an open mouth of the housing. A manifold formed by the inner surfaces of the housing and the inner cap member is used to recombine the four separate planar wavefronts back into a single composite wavefront emanating from the open mouth of the housing.