Earphone system and use of an earphone system

There is provided an earphone system comprising an earphone and at least two acoustic dampers (24), the earphone comprising a speaker unit (10) and an earpiece (12, 12A, 12B), the speaker unit comprising a sound driver (18), a wiring connector (14) for providing audio signals to the sound driver and a case (16) housing the sound driver, the earpiece comprising a sound outlet opening (28) and being designed for being worn in a user's ear canal and/or concha, the sound driver having a frequency response having a maximum within the range of 2000 Hz to 4000 Hz, wherein the speaker unit is for being inserted into the earpiece, wherein each of the acoustic dampers (24) is for being inserted into the earpiece or the speaker unit in an exchangeable manner and wherein each of the acoustic dampers, when used with the earphone, has a frequency response different from that of the other acoustic damper(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase entry of prior PCT Application No. PCT/EP2008/004094 filed May 21, 2008 and entitled “EARPHONE SYSTEM AND USE OF AN EARPHONE SYSTEM”, the disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an earphone comprising a speaker unit and an earpiece for being worn in a user's ear canal and/or concha; the invention also relates to the use of such an earphone.

2. Description of Related Art

In general, the earpiece of an intra-auricular earphone may be of the “one-size-fits-all” or generic type, wherein the earpiece comprises a shell made of a soft, flexible material and having an outer surface of standard shape, with the soft earpiece, typically delivered in a number of sizes (typically 3 or 4), adapting to the individual shape of the user's concha and ear canal due to its flexibility.

Alternatively, the earpiece may comprise a shell made of a relatively hard material and having an outer surface individually shaped according to the measured inner shape of the user's ear canal and outer ear. The measurement usually is done by taking an impression of the user's ear and subsequent laser scanning of the impression or by direct laser scanning of the user's ear. Such earpieces are known as customized earpieces. Earphones comprising a customized shell described, for example, in US 2004/0201139 A1, DE 101 11 636 B4, DE 10 2006 007 032 A1, EP 1 629 808 A1, EP 1 595 515 A1, GB 2,355,129 A, U.S. Pat. No. 7,139,404 B2 and U.S. Pat. No. 7,016,512.

U.S. Pat. No. 7,139,404 B2 and U.S. Pat. No. 7,016,512 relate to modular systems including a CIC (Completely-In-the-Canal) earphone comprising an earpiece, which may be either generic or customized and into which a speaker unit is inserted in a detachable manner, with the speaker unit being connected by wires to a BTE (Behind-The-Ear) component. The system may be used as an earphone for music from an external device or as a stage monitor for musicians. Also US 2007/0036385 A1 and US 2007/0053540 A1 relate to modular earphones comprising a speaker unit, which is inserted into an earpiece, wherein the earpiece could be either a generic earpiece or a customized earpiece and wherein the earpiece may be replaced, if the earpiece deteriorates during use; the speaker unit may comprise a two-way speaker.

US 2006/0285715 A1, U.S. Pat. No. 5,878,070 and the Knowles Application Note concerning TI-29, Report 10559-2 by M. T. Killion, relate to high end earphones comprising an acoustic damper and a resonator portion for optimizing the frequency response of the earphone, wherein the damper and the resonator portion are part of the speaker unit which is connected to an earpiece. The damper is provided within the resonator which may be a quarter-wave resonator, and is replaceable by a damper of the same kind if the damper becomes deteriorated during use of the earphone.

When an intra-auricular earphone, which closes the ear canal, is worn, the transfer function of the ear is changed in that the quarter-wave resonance of the ear canal and the amplification of the pavilion disappears, which effects cause an uncomfortable sensation to the user. Hence, it is desirable to provide the earphone with a frequency response suitable for restoring the natural open ear gain, in particular, the quarter wave resonance of the ear canal, as far as possible in order to provide for a natural hearing impression to the user when wearing the earphone.

It is an object of the invention to provide for an intra-auricular earphone which allows for an optimization of the frequency response, and, in particular, for an individual adjustment of the frequency response of the earphone to the specific user in a particularly simple manner.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved by an earphone as defined in claim1and a use as defined in claim23, respectively.

This solution is beneficial in that, by providing an earphone system with a plurality of exchangeable acoustic dampers, and, in particular, by testing different acoustic dampers with the earphone until a final acoustic damper has been found, which, when used with the earphone, imparts a final frequency response to the earphone, which more closely approaches the user's natural open ear gain or listening preferences than the other acoustic dampers, the acoustic performance of the earphone can be individually optimized in a simple manner after manufacturing of the earphone.

According to one embodiment, the user's natural open ear gain may be measured for selecting the final acoustic damper.

Preferably, at least the acoustic damper is integrated in the earpiece. By integrating at least the acoustic damper in the earpiece, with the earpiece being connected in a detachable manner to the speaker unit and hence being exchangeable, the most critical acoustic element is located in an exchangeable and hence individually adjustable element, namely the earpiece, and hence can be optimized with regard to the respective user. Thereby a particularly reliable adjustment of the frequency response of the earphone is enabled, which in particular allows for high fidelity sound reproduction. In particular, the length of the resonator, which preferably is a quarter-wave resonator, is very critical and has to be designed very precisely, since an inaccuracy of only a few millimeters can dramatically influence the frequency response. Such precise and individual optimization of the sound quality would not be possible, if the resonator would be part of the usually standardized speaker unit.

According to one embodiment, also the acoustic damper is intergrated in the earpiece, whereby a particularly reliable adjustment of the frequency response of the earphone is enabled.

According to an alternative embodiment, the acoustic damper is part of the speaker unit.

Preferably, the earpiece is a customized earpiece comprising a hard shell having an outer surface individually shaped according to the measured inner shape of the user's ear canal and outer ear, with the shell preferably being produced by a three-dimensional printing process. By using a customized earpiece, the resonator can be individually optimized in a particularly simple manner.

Preferably the resonator is designed for increasing the gain of frequencies above 10 kHz and the acoustic damper is located upstream of the resonator. Typically, the sound driver has a frequency response having a global maximum within the range of 2000 Hz to 4000 Hz, in order to enable restoration of the quarter-wave resonance of the ear canal. The acoustic damper is designed for affecting the frequency response of the earphone primarily in the frequency range of the user's natural ear resonance, in particular primarily in the frequency range of the resonance of the sound driver.

The sound driver may include an armature transducer or a dynamic diaphragm transducer, a back vent, a plurality of transducers, a passive electrical filter and at least one non-exchangeable acoustic damper.

It is also an object of the invention to provide for a use of an earphone system, wherein the user is enabled to choose the earphone system in a particularly comfortable and reliable manner.

According to the invention, this object is achieved by a use as defined in claim14.

This solution is beneficial in that, by first connecting the speaker unit to a generic test earpiece, thereby forming a test earphone having a test frequency response, the user may test the acoustic performance of the test earphone before deciding that a costly customized earpiece should be manufactured for forming the final earphone for long-term use, with the final earphone having essentially the same acoustic performance as the test earphone.

Preferably, the earphone system comprises an acoustic damper and a resonator, which, according to one embodiment, are provided as part of the speaker unit and, according to an alternative embodiment, are provided as part of each of the earpieces.

Further preferred embodiments of the invention are mentioned in the dependent claims.

These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1A and 1Bshow an example of an earphone according to the invention, comprising a speaker unit10and an earpiece12. The speaker unit10comprises a wiring connector14for supplying audio signals from an audio signal source (not shown) which may be, for example, a portable audio player, a home hi-fi device, a professional sound device, a wireless high frequency receiver for audio monitoring, etc., and a rigid case16housing a sound driver18. The earpiece12comprises a shell or ear tip20, a generic case22and an exchangeable acoustic damper24. The generic case22of the earpiece12comprises a resonator26is located between the acoustic damper24and a sound outlet opening28at the inner end of the earpiece12. The resonator26may be designed as a quarter-wave resonator or as an expansion horn.

The wiring connector14may be detachable plug/socket connection, as shown inFIGS. 1A and 1B, or it may be a wiring element fixedly connected to the speaker unit10, as shown inFIGS. 10A and 10B.

In the embodiment ofFIGS. 1A,1B the earpiece12is a generic earpiece, i.e. the shell20is made of a relatively soft material, for example, silicon, and it has an outer surface of standard shape. For fitting the earpiece12to different ear sizes the shell20may be provided in different sizes. The shell20may be connected to the generic case22in a detachable manner in order to exchange the shell20, for example, if deteriorated during use.

The speaker unit10is connected to the earpiece12in a detachable manner by inserting the front end of the rigid case16into the generic case22of the earpiece12.

The sound driver18usually has a frequency response having a maximum within the range of 2000 Hz to 4000 Hz, preferably 2700 Hz, in order to enable restoring the user's natural ear resonance which is otherwise destroyed by the missing open ear gain when wearing an earphone. The output port of the sound driver18is acoustically connected with the exchangeable acoustic damper24which reduces the level of the sound driver peak according to its specific acoustic resistance value but which has relatively little influence on the frequency response of the system at other frequencies, i.e. the acoustic damper24is designed for affecting the frequency response of the earphone primarily in the frequency range of the maximum of the sound driver18. If an acoustic damper24having a relatively low acoustic resistance is selected, the level of the maximum of the sound driver18is high, so that the open ear gain of the user is essentially fully compensated; if an acoustic damper24having a relatively high acoustic resistance is selected, the level of the sound driver maximum is low and the open ear gain is less compensated. By selecting the type of acoustic damper24the frequency response of the earphone can be tuned to the individual preference and individual natural open ear gain of the user. The option for such individual adjustment is important, because the natural open ear gain, and in particular the level of the natural open ear resonance, is quite different for different persons, as shown inFIGS. 7A and 7B, where the variation of the natural open ear gain vs. frequency for different persons is shown.

The acoustic damper24is also acoustically coupled with the resonator26which is designed for increasing the high frequencies above 10 kHz for enabling high fidelity applications of the earphone. InFIG. 8examples of the frequency response of the earphone are shown for four different types of acoustic dampers24. It can be seen inFIG. 8how the amplitude and to some extent also the position of the peak of the frequency response in the region of the natural open ear gain can be adjusted by selecting the appropriate acoustic damper24.

FIG. 9shows another example of the frequency response of an earphone according to the invention, wherein the resonance of the sound driver18provides for a global maximum in the region around 2700 Hz and wherein the effect of the resonator26enhances the high-frequency response due to resonances above 10 kHz.

In order to optimize the frequency response of the earphone, first a test acoustic damper24may be inserted into the earpiece case22, thereby forming a test earphone having a test frequency response, which test earphone then is inserted into the user's ear for testing the acoustic performance of the test earphone. Thereafter, the earphone is removed from the user's ear and the test acoustic damper24is replaced by an acoustic damper24of a different type, i.e. having a different acoustic resistance, with the earphone obtained thereby being inserted again into the user's ear, in order to test the acoustic performance of the earphone using this different acoustic damper. This procedure of testing an acoustic damper of a different type may be repeated, until a desired final frequency response is obtained by a final earphone using a final acoustic damper24, which approaches the user's natural open ear gain or listening preferences more closely than the test dampers tested before. The final earphone is selected for long-term use. Testing of the frequency response may be effect by simply using the user's judgement. Optionally, the user's natural open ear gain may be measured for selecting the final acoustic damper24. Conveniently a tool may be provided for exchanging the acoustic dampers24.

InFIGS. 2A and 2Ban embodiment is shown wherein the generic earpiece12is replaced by a customized earpiece12having a hard shell20having an outer surface individually shaped according to the measured inner shape of the user's ear canal and outer ear in order to achieve optimized fit of the earpiece12. The hard shell20may be produced, for example, by a three-dimensional printing process, with the shape of the user's ear canal and outer ear being measured, for example, by taking a silicon ear impression which is then scanned or by direct ear scanning, with the data obtained by the scanning process being imported to a modelling software which controls a 3D-printer in order to assemble the shell20.

In the example shown inFIG. 2Bthe rigid case16of the speaker unit12is inserted in a detachable manner into a fixation system30provided in the interior of the shell20.

Preferably, the speaker unit10and all kind of earpieces12are designed in such a manner that the speaker unit10can be used with any type of the earpieces12. This is illustrated in the example shown inFIG. 3, according to which a speaker unit10may be used alternatingly with an earpiece12A comprising a soft generic shell20A and a customized earpiece12B comprising a customized hard shell20B.

By using this principle, the user of the earphone may test the acoustic performance of the earphone by connecting the speaker portion10to the generic earpiece12A in order to judge whether he actually wants to purchase an earphone comprising the speaker unit10, i.e. a test earphone is created by connecting the speaker unit10to the generic earpiece12A. Once the user has decided to purchase the earphone, a customized earpiece12B comprising a customized shell20B will be manufactured based on a measurement/impression of the user's ear canal and outer ear.

The earpieces12are designed in such a manner that they are of the intra-auricular type, i.e. they are worn in the user's ear canal and/or the user's concha.FIG. 6Ashows an example of a customized earpiece12which is designed for being worn only in the ear canal (intra-canal), andFIG. 6Bshows an example of a customized earpiece12of the full concha type.

In the embodiments shown inFIGS. 1 and 2the resonator26and the acoustic damper24are part of the earpiece12. Since elements these are the most sensible acoustic elements for the coupling with the ear, this arrangement allows for excellent acoustic optimization, in particular, if the earpiece is of the customized type. An alternative embodiment is shown inFIG. 4, wherein the rigid case16of the earpiece speaker unit10is designed in such a manner that it includes the resonator26, the sound opening28and the acoustic damper24. In this case, the earpiece12essentially consists of the shell20, into which the front end of the case16is inserted. In the embodiment shown inFIG. 4the shell20is of the generic soft type.

FIG. 5shows an example of the sound driver18, comprising electrical wirings32, a passive electrical filter34, a high frequency sound transducer36, a low-frequency sound transducer38, non-exchangeable internal acoustic dampers40for the sound transducers36and38and an output port42to the exchangeable acoustic damper24. The dampers40also could be included in the output port42. The sound transducers38,40may be armature transducer or dynamic diaphragm transducers. The sound driver18also may include a back vent (not shown inFIG. 5).

In all embodiments the exchangeable acoustic damper24also may serve as an ear wax protector.

FIGS. 10A and 10Bshow embodiments, wherein the rigid case16of the earpiece speaker unit10is designed in such a manner that it includes the acoustic damper24, whereas the resonator26and the sound opening28are part of the earpiece12A,12B into which the front end of the case16is inserted. In the embodiment shown inFIG. 10Athe shell20A is of the generic soft type; In the embodiment shown inFIG. 10Athe shell20B is of the customized type. The case16of the speaker unit10is designed such that the speaker unit10may be used either the generic earpiece10A or the customized earpiece10B.

While various embodiments in accordance with the present invention have been shown and described, it is understood that the invention is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, this invention is not limited to the details shown and described herein, and includes all such changes and modifications as encompassed by the scope of the appended claims.