The casing of a hearing aid can be acoustically dampened and its receiver is less likely to amplify noise stemming from vibrations of the casing when the casing is lined with a viscoelastic material. The viscoelastic lining can be applied by laying a viscoelastic layer across the rim of the casing and drawing a vacuum at the sound-communicating orifice of the casing until the viscoelastic is drawn tightly against the interior of the casing. A preferred viscoelastic layer has at one surface a substance such as fibers or beads that will form temporary bridges to permit an air to be evacuated between the viscoelastic layer and a casing to which it is applied. When the deposited viscoelastic is tacky at room temperature, the components of the hearing aid can be positioned simply by pressing them into the viscoelastic material, thus making the assembly easier than prior methods of assembling tiny hearing aids.
A method and apparatus for reducing distortion of an acoustical waveform by locating a plurality of microspheres to interact with interfering acoustical waveforms are described.
A support pad for use in a hearing device of the type comprising a casing having an inner surface defining a cavity; and a sound receiving, amplification and transmitting system within the cavity in the casing, which system includes a transducer. The support pad includes a layer of conformable metal having first and second opposite major surfaces, and a layer of viscoelastic material along its first major surface. The support pad has an attachment portion with the layer of viscoelastic material along the attachment portion being adapted to be adhered to a side surface of the transducer, and has at least one tab portion adapted to project away from the transducer adjacent an end of the transducer. The tab portion is adapted to be shaped so that the second major surface along the tab portion is adjacent and conforms to the inner surface of the casing and can be adhered to the inner surface of the casing with the tab portion shaped and positioned so that the attachment portion of the support pad and the transducer are spaced from the inner surface of the casing.
The invention relates to an active hearing protection earplug comprising a shell (2000) to be worn at least in part in a user's ear canal and being adapted to attenuate sound waves arriving at the outer end (2001) of the shell, and an active system (2002, 2010) comprising an input transducer (2024) for converting ambient sound into audio signals, an audio signal processing unit (2028) for processing said audio signals, and an output transducer unit (2010) mounted within the shell for converting said processed audio signals into sound output at the inner end of the shell, wherein the amplification of the active system is negative and wherein the output transducer unit comprises at least two separate outputs (2032, 2034). The invention also relates to a method for manufacturing such an earplug.
A hearing aid includes an electronic assembly mounted in a cylindrical shell with the shell being mounted in an opening in a ear mold. The electronics assembly includes a printed circuit strip having thereon a speaker, a microphone and electronic components forming a signal processing circuit for amplifying the sound. The ear mold is of a soft, durable and compliant material so that it will fit tightly in the ear of a user. The hearing aid is of optimum design having a minimum number of components and is easy to assemble on an automatic basis. This provides a hearing aid which is relatively inexpensive so as to be disposable.
A hearing aid of conventional configuration comprising a microphone at one end adapted to be placed in the inlet of the external auditory meatus, a loudspeaker at the other end adapted to be placed within the auditory meatus, and an amplifying device between the microphone and the loudspeaker, has a means (26) of sound-dampening materials over the microphone to prevent that sound directly impinges upon the latter, but is provided with a passage (27) containing a sound-transmitting medium and directed towards the inner side of one of the parts of the auricle (10), preferably the tragus (14), so that only sound picked up and treated by the auricle (10) is supplied to the loudspeaker.
