An earphone device converts electric signals to audible sound. The device includes an outer area configured to receive a power source. A plug area adjacent to the outer area may be configured to fit within a user's auditory canal. A dynamic transducer reproduces a predetermined frequency spectrum for the user. A sound channel terminating at an output of the dynamic transducer encloses the second transducer.

BACKGROUND OF THE INVENTION

This application claims the benefit of priority from EP 08450034.7, filed Mar. 12, 2008, which is incorporated by reference.

This disclosure relates to devices that convert one form of energy into another and particularly to systems that convert electric energy into non-electric energy.

Earphones convert electric signals into audible sound. They may compensate for impaired hearing, deliver music, radio programs, or be used to communicate with others. Many devices are worn behind or fit over a user's ear. Besides the discomfort and unsightly appearance, some devices over compensate for noisy environments by over amplifying sound at the outer ear.

SUMMARY

An earphone device converts electric signals into audible sound. The device includes an outer area configured to receive a source of power. A plug area adjacent to the outer area may be configured to fit within a user's auditory canal. A dynamic transducer reproduces a predetermined frequency spectrum for the user. A sound channel terminating at an output of the dynamic transducer encloses the second transducer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An earphone system converts electric signals into audible sound. The system includes devices that convert one form of energy into another. In some systems it may include a balanced armature (BA) transducer or a piezoelectric transducer. The transducer may be positioned in a plug area and may lie in a sound channel of a dynamic transducer (e.g., a device that may reproduce low and/or high frequency spectrum or aural sound). In some applications, the internal front volume of the earphone is reduced to about 40 mm3with the entire front volume reduced from about 815 mm3to about 713 mm3.

In some earphones the acoustic outlet of the BA transducer (e.g., a transducer that may move less air than a dynamic transducer) is positioned adjacent to the acoustic outlet of a dynamic transducer. The acoustic outlet may be directed away from the end of the sound channel. High quality intelligibility is achieved because the earphone is less sensitive to leakage. Musical tones (e.g. tonality) may be reproduced fluidly, dynamically, and clearly through the dynamic transducer.

FIG. 1is an earphone100that includes a housing101and an ear cushion102. The ear cushion102may be situated in the auditory canal. Two BA transducers103and104are exposed to signals through a frequency divider network107. The BA transducers103and104transmit acoustic waves through sound channels105and106, which are positioned substantially parallel and flow in the direction of the auditory canal. Power is sourced to the earphone100through a cable and a lead-through108.

FIG. 2is an alternate earphone system200. In the earphone system200a BA transducer104communicates through sound channel203. A dynamic transducer202communicates with a separate sound channel201. In this system, the BA transducer104receives input from a frequency divider network107. The sound channels201,203, are positioned in parallel and may be partially received by the auditory canal.FIG. 3is an alternate earphone300having sound channels106,201that terminate at a common end channel301. The common end channel passes through the ear cushion102of the earphone300.

FIG. 4is an in-ear earphone device400. The earphone device400converts electric signals that may include telephone, stereo, or other transmitted signals to audible (or aural) sound. In the earphone device400, a plug area410may be positioned in a narrow tube-like passage that terminates at the tympanic membrane (in the auditory canal). A notch or channel separates the plug area410from the outer area411. The width and length of the separation established by the notch may vary with an application. In some alternate systems the plug area410and outer area411comprise a unitary element.

The earphone400includes a BA transducer402and ear (or air) cushions102. When worn, the oval cylindrical shape of the auditory canal may receive the BA transducer402positioned in front of a dynamic transducer202. Sound channel403also encloses the BA transducer402. Miniaturization may be facilitated by the configuration of the transducers that are positioned to render a strong coincidence. In some systems, it is facilitated by a sound outlet405of the BA transducer402lying in a sound channel403of a dynamic transducer202(see alsoFIG. 8). The cavity or channel positioned “in front” of the dynamic transducer202may be sealed to form a closure against air (e.g., airtight) and other external elements thereby allowing the sound outlet403to serve as a sound channel. Control lines from the frequency divider network107may be guided to the BA transducer402by passing through a portion of the seal404or may not be used when wireless connections and other portable power sources are used. The sound opening412of earphone400and output of the BA transducer402may terminate at a proximal portion of the plug area410. When worn, the sound opening412may face or communicate with the tympanic membrane.

FIG. 5shows an alternative ear piece system500. InFIG. 5, the BA transducer502lies in an “inverted” position. The sound outlet504may face an output of the dynamic transducer202. In this system, the sound paths of the BA and dynamic transducers202,502may be approximately the same size. Similarly sized sound paths may improve coincidence and sound quality.

FIG. 6is an alternate ear piece that includes two or more BA transducers (402and602are shown). A sound outlet504of BA transducer402may be directed toward or face a distal end of BA transducer602. In this arrangement the sound outlets504and604may face or be directed to the proximal end of the earphone system600.

FIG. 7is an ergonomic earphone system700. The earphone system700includes a dynamic transducer202inclined or oblique to a central axis712of the BA transducer402. The central axis712may form a line of symmetry to the ear cushion102. A common arcuate flexible sound channel703may diverge from the central axis712. InFIG. 7, the line of symmetry of the sound channel forms an obtuse angle with the line of symmetry (e.g., central axis712) of the BA transducer402. A portion of the arcuate transition may be coincident with the oval cylindrical canal of a user's auditory canal.

The flexibility and configuration ofFIG. 7may improve comfort without reducing sound quality. In some alternate systems, the BA transducer may be positioned in an inverted position in which the sound outlet504of transducer402may be directed toward an output of the dynamic transducers202. In this arrangement, coincidence may improve.

FIG. 8is a top view ofFIG. 4in from the direction of arrow VIII. InFIG. 8the sound channels of the transducers402and202are coincident. The BA transducer402is enclosed by the sound channel403, ear cushion102, and housing401. The sound outlet405of BA transducer may be visible in the area of a central recess of the air cushion.

FIG. 9illustrates the emitted sound pressure simulated in an artificial ear. Four curves that correspond to front volumes of 0.1 cm3, 0.4 cm3, 0.7 cm3and 0.9 cm3are plotted on a logarithmic scale against the frequency between about 100 Hz and about 20 kHz. The maxima of the curves that form at the resonance frequency are shifted to higher frequencies at smaller front volume showing the improvement when compared to known devices.

Other alternate systems may include combinations of some or all of the structures described above or shown in the figures. These systems may be formed from any combination of structure or functions described. In some systems different transducers are used and dimension may vary. For example, some alternate earphone systems use three or more transducer having outputs facing a common direction or some or all aligned in inverted positions. The shape of the sound channels that may lie in a listener's auditory canal may enclose two, three, or more transducers (e.g., BA, dynamic, etc.). In some systems only a subset of the first transducer, the second transducer, and the third transducer may lie in a common channel or within a user's auditory canal. The shape of the channel may vary. Other alternate systems (including those shown) may not include or interface a frequency divider network and some or all of the transducers may be connected in parallel.

Each of the systems described may include special sound outlet openings. When a transducer is arranged in a plug area410of the earphone, it may face corresponding second transducer (or third, or fourth, or fifth, etc.). These arrangements may improve coincidence.