Earmold for active occlusion cancellation

An earmold for an ear canal of a user, the earmold having an earmold shell and extending along an axis, the earmold shell having a tip end, the tip end facing a tympanic membrane of the user when worn by the user, the earmold includes: a first microphone connected to a first microphone opening for receiving sound in the ear canal, wherein the first microphone opening is arranged in a first position at a first distance from the tip end of the earmold shell; and a receiver opening for providing sound in the ear canal, wherein the receiver opening is arranged in a second position at a second distance from the tip end of the earmold shell; wherein the first position is different from the second position.

FIELD

The present disclosure relates to an earmold and in particular to earmold, device and methods for active occlusion cancellation in a hearing device, such as a headset or a hearing aid.

BACKGROUND

Occlusion has for long been recognized as a problem for some hearing aid users, and continuous efforts have been made to reduce the occlusion effect.

Known solutions to reduce the occlusion effect provide a vent in the earpiece or earmold in order to allow pressure equalization between the ear canal and the surroundings.

Further, active occlusion cancellation (AOC) systems have been developed, the AOC systems having a canal microphone in the ear canal and being arranged along with the receiver at the tip of the earmold.

SUMMARY

Despite the known solutions there is still a need for improved occlusion cancellation, in particular in a hearing device.

Accordingly, an earmold for an ear canal of a user is provided, the earmold having an earmold shell and extending along an axis, the earmold shell having a tip end, the tip end facing a tympanic membrane of the user when worn by the user, the earmold comprising a first microphone connected to a first microphone opening for receiving sound in the ear canal, wherein the first microphone opening is arranged in a first position at a first distance from the tip end; and a receiver opening for producing sound in the ear canal, wherein the receiver opening is arranged in a second position at a second distance from the tip end. The first position may be different from the second position.

Also disclosed is a hearing device comprising an earmold as disclosed herein, the hearing device or the earmold comprising a processing unit connected to the receiver and the first microphone, wherein the processing unit comprises an occlusion cancelling unit configured to modify an output signal to the receiver based on an input signal from the first microphone.

It is an important advantage that near field effects of the receiver and/or the vent are substantially reduced, thus providing improved occlusion cancellation.

Further, it is an advantage that a more controlled closed loop transfer function for active occlusion cancellation is provided, which in turn facilitates improved occlusion cancellation.

Advantageously, the earmold enables a more accurate measurement/determination of in-situ canal sound pressure for higher frequencies.

An earmold for an ear canal of a user, the earmold having an earmold shell and extending along an axis, the earmold shell having a tip end, the tip end facing a tympanic membrane of the user when worn by the user, the earmold includes: a first microphone connected to a first microphone opening for receiving sound in the ear canal, wherein the first microphone opening is arranged in a first position at a first distance from the tip end of the earmold shell; and a receiver opening for providing sound in the ear canal, wherein the receiver opening is arranged in a second position at a second distance from the tip end of the earmold shell; wherein the first position is different from the second position.

Optionally, the first microphone opening and the receiver opening are offset from each other in a direction that is perpendicular to the axis.

Optionally, the first distance is smaller than the second distance.

Optionally, a distance between the first position and the second position is at least 1 mm.

Optionally, a distance between the first position and the second position is anywhere from 1.5 mm to 5 mm.

Optionally, the earmold further includes a vent channel with a vent opening for venting the ear canal, wherein the vent opening is arranged in a third position at a third distance from the tip end along the axis, and wherein the first position is different from the third position.

Optionally, a distance between the first position and the third position is at least 1 mm.

Optionally, a distance between the first position and the third position is anywhere from 1.5 mm to 5 mm.

Optionally, the second position is different from the third position.

Optionally, the first distance is less than 1 mm.

Optionally, the first microphone opening and/or the receiver opening are arranged in the earmold shell.

Optionally, the earmold further includes a microphone tube extending from the earmold shell, wherein the first microphone opening is at a distal end of the microphone tube.

Optionally, the earmold further includes a receiver tube extending from the earmold shell, wherein the receiver opening is at a distal end of the receiver tube.

Optionally, the earmold further includes a receiver connected to the receiver opening.

A hearing device includes the earmold, the hearing device comprising a processing unit connected to a receiver and a microphone, wherein the processing unit comprises an occlusion cancelling unit configured to provide an output signal to the receiver based on an input signal from the microphone.

Other and further aspects and features will be evident from reading the following detailed description.

DETAILED DESCRIPTION

The earmold has an earmold shell. The earmold shell has an outer surface. The outer surface may be configured to fit into the ear canal of a user of the earmold.

The earmold extends along an axis. The axis may be parallel to the longitudinal direction of the earmold. The axis may be substantially parallel with the ear canal i.e. within 2-5 degrees.

The earmold has a tip end (distal end) with a tip surface facing a tympanic membrane of the user when worn by the user. The axis may perpendicular to or substantially perpendicular to the tip surface. The tip surface may be plane or rounded. Further, the earmold has a proximal end. The earmold may have a proximal surface facing away from the tympanic membrane when worn by the user.

The earmold comprises a first microphone, also denoted canal microphone, connected to a first microphone opening for receiving sound in the ear canal. The first microphone acting as an ear canal microphone may be connected to the first microphone opening via a microphone duct formed by a microphone tube and/or a microphone channel in the earmold shell. The first microphone opening may be perpendicular to the axis or angled e.g. with an angle in the range from 70 degrees to 110 degrees, thus pointing into the ear canal of a user.

The first microphone opening is arranged in a first position at a first distance from the tip end (measured along the axis). The first distance may be in the range from 0 to 8 mm. The first microphone opening may be arranged near or at the tip end. For example, the first distance may be less than 2 mm. The first microphone opening may be arranged between the tip end and the proximal end of the earmold. The first microphone opening may be arranged between the tip end and the tympanic membrane. The first microphone opening may have a diameter of at least 0.5 mm.

The earmold comprises a receiver opening. The earmold may comprise a receiver connected to the receiver opening for producing sound in the ear canal. The receiver may be connected to the receiver opening via a receiver duct formed by a receiver tube and/or a receiver channel in the earmold shell. The receiver opening may be perpendicular to the axis or angled e.g. with an angle in the range from 70 degrees to 110 degrees, thus pointing into the ear canal of a user.

The receiver opening is arranged in a second position at a second distance from the tip end (measured along the axis). The second distance may be in the range from 0 to 8 mm. The first microphone opening and the receiver opening may be separated in a transverse plane perpendicular to the axis such that the first microphone opening and the receiver opening do not coincide. The receiver opening may have a diameter of at least 0.5 mm.

The first microphone opening and the receiver opening may be separated when projected onto a transverse plane perpendicular to the axis.

The first distance may be the same as or different from the second distance. The distance between the first position and the second position may be at least 1 mm. The distance (measured along the axis) between the first position (first microphone opening) and the second position (receiver opening) may be in the range from 1.5 mm to 5 mm.

The first distance may be smaller than the second distance.

The first microphone opening and the receiver opening may have a transverse distance (first transverse distance) of at least 1 mm, such as in the range from 2 to 5 mm. The transverse distance between two openings is the distance between respective centers of the two openings projected onto a plane perpendicular to the axis.

The earmold may comprise a vent channel with a vent opening for venting the ear canal, wherein the vent opening is arranged in a third position at a third distance from the tip end (measured along the axis). The first microphone opening and the vent opening may be separated in a transverse plane perpendicular to the axis such that the first microphone opening and the vent opening do not coincide. The vent opening may have a diameter of at least 0.5 mm.

The first distance may be the same as or different from the third distance. The distance between the first position and the third position may be at least 1 mm. The distance between the first position and the third position may be in the range from 1.5 mm to 5 mm.

The second distance may be different from the third distance. The second position may be the same as or different from the third position. The distance between the second position and the third position may be at least 1 mm. The distance between the second position and the third position may be in the range from 1.5 mm to 5 mm.

The distance between the second position and the third position may less than 1 mm.

The first microphone opening and the vent opening may be separated when projected onto a transverse plane perpendicular to the axis. The first microphone opening and the vent opening may have a transverse distance (second transverse distance) of at least 1 mm, such as in the range from 2 to 5 mm. The receiver opening and the vent opening may have a transverse distance (third transverse distance) of at least 1 mm, such as in the range from 2 to 5 mm.

The first microphone opening and/or the receiver opening may be arranged in the earmold shell.

The first microphone opening, the receiver opening and the vent opening may be arranged along a straight line perpendicular to the axis. The first microphone opening, the receiver opening and the vent opening may be arranged in a triangle when seen from the tip end, e.g. a triangle where all angles are less than 100 degrees, such as less than 80 degrees.

The earmold may comprise a microphone tube extending from the earmold shell with the first microphone opening formed at a distal end of the microphone tube. Hereby, the first microphone opening may be positioned close to the tympanic membrane, which may be desirable to obtain accurate determination of sound pressure variations.

The earmold may comprise a receiver tube extending from the earmold shell with the receiver opening formed at a distal end of the receiver tube. Hereby, the receiver opening may be positioned close to the tympanic membrane, which may be desirable to obtain improved audio transfer from the receiver to the tympanic membrane.

The earmold may comprise a vent tube extending from the earmold shell with the vent opening formed at a distal end of the vent tube.

The earmold or a hearing device comprising the earmold may comprise a processing unit connected to the receiver and the first microphone, wherein the processing unit comprises an occlusion cancelling unit configured to modify an output signal to the receiver based on the signal to the first microphone.

The earmold may comprise a second microphone for receiving sound from the surroundings. The second microphone or an associated second microphone opening may be positioned in a proximal surface of the earmold and/or in proximity to the proximal end. One or more second microphones may be arranged in a hearing aid housing or part external to the earmold.

The processing unit may be connected to one or more second microphones for receiving sound from the surroundings, wherein the processing unit comprises an occlusion cancelling unit configured to modify an output signal to the receiver based on an input signal from the first and second microphones.

The hearing device may be a receiver-in-the-ear (RITE) hearing device, or a receiver-in-canal (RIC) hearing device. The hearing device may be a behind-the-ear (BTE) hearing device, e.g. where the receiver is arranged in a housing configured to be positioned behind the ear of a user.

The hearing device may be a hearing aid, i.e. with a processing unit configured to compensate for hearing loss of a user.

FIG. 1schematically illustrates an exemplary earmold for an ear canal of a user. The earmold2has an earmold shell4and extends along an axis X. The earmold2has a tip end6with a tip surface7facing a tympanic membrane (not shown) of the user when worn by the user. The axis X is perpendicular to the tip surface7. The earmold2comprises a first microphone (canal microphone)8connected to a first microphone opening10for receiving sound in the ear canal. The first microphone opening10is arranged in a first position at a first distance d1from the tip end6along the axis X. InFIG. 1, the first microphone opening is arranged in the tip surface, i.e. the first distance d1=0. The first microphone8is connected to the processing unit30via first conductor11for feeding an input signal from the first microphone8to the processing unit30. Further, the earmold2comprises a receiver12connected to a receiver opening14for producing sound in the ear canal, wherein the receiver opening14is arranged in a second position at a second distance d2from the tip end6along the axis X. The second distance d2=2 mm, thus the first distance d1is different from the second distance d2. Displacement of the first microphone opening and the receiver opening along the axis X reduces near field effects of the receiver, especially at high frequencies, leading to improved and more precise in-situ canal pressure measurements performed by canal microphone8. The receiver12is connected to the processing unit30via second conductor15for receiving output signal from the processing unit30. The first microphone opening10is arranged in a microphone plane P1perpendicular to the axis X. The receiver opening14is arranged in a receiver plane P2perpendicular to the axis X.

The earmold2comprises a vent channel16with a vent opening18for venting the ear canal. The vent opening18is arranged in a third position at a third distance d3(d3=3 mm) from the tip6end along the axis X. The vent opening18is arranged in a vent plane P3perpendicular to the axis X.

In one or more exemplary earmolds, microphone plane P1, receiver plane P2, and vent plane P3may be non-perpendicular to the axis X. Microphone plane P1and receiver plane P2may be non-parallel. Microphone plane P1and vent plane P3may be non-parallel. Receiver plane P2, and vent plane P3may be non-parallel.

FIG. 3shows an exemplary end view of an earmold, e.g. g the earmold2. The first microphone opening10, the receiver opening14, and the vent opening18are arranged in first surface20, second surface22, and third surface24, respectively, of the earmold shell4. The first position is closest to the tip end compared with the second position and/or the third position. In the earmold2, the first surface20corresponds to the tip surface7. As can be seen fromFIG. 3, the openings10,14, and18are not coinciding in a transverse plane perpendicular to the axis X i.e. the transverse distances between the openings10,14, and18are non-zero.

Returning toFIG. 1, the earmold2comprises a second microphone32connected to the processing unit30via third conductor31for receiving an external input signal from the second microphone32to be compensated according to a hearing loss of the user wearing the earmold by the processing unit30. The second microphone32and the processing unit30are accommodated within the earmold shell4. In one or more alternative earmolds, the second microphone32and/or the processing unit30may be positioned external to the earmold shell4.

The earmold2may comprise a microphone tube extending from the earmold shell with the first microphone opening formed at a distal end of the microphone tube as shown inFIG. 6. The earmold2may comprise a receiver tube extending from the earmold shell with the receiver opening formed at a distal end of the receiver tube as shown inFIG. 8.

FIG. 2illustrates an exemplary earmold102similar to the earmold2. In the earmold102, the receiver opening14is arranged closer to the tip end (d2=0) than the first microphone opening (d1=2 mm). The conductors11,15are connected to a processing unit (not shown) for performing occlusion cancellation in the output signal to the receiver12based on the input signal from the first microphone8.

FIG. 3is an end view of an exemplary earmold, such as earmold2. The first microphone opening10is arranged in the first surface20of the earmold shell4being the tip surface7. The receiver opening14is arranged in the second surface22of the earmold shell4and the vent opening18is arranged in the third surface24of the earmold shell4. The transverse distance between the first microphone opening10and the receiver opening14is 2 mm. The transverse distance between the first microphone opening10and the vent opening18is 4 mm. The transverse distance between the receiver opening14and the vent opening18is 2 mm.

FIGS. 4 and 5illustrate an exemplary earmold202. The receiver opening14and the vent opening18are arranged at the same distance from the tip end6along the axis X. The transverse distance between the first microphone opening10and the receiver opening14is 2 mm. The transverse distance between the first microphone opening10and the vent opening18is 2 mm. The transverse distance between the receiver opening14and the vent opening18is 4 mm. The openings10,14, and18are not coinciding in a transverse plane perpendicular to the axis X i.e. the transverse distances between the openings10,14, and18are non-zero.

FIG. 6illustrates an exemplary earmold302. The earmold302comprises a microphone tube34extending from the earmold shell4with the first microphone opening10formed at a distal end of the microphone tube34. The first microphone opening10can be positioned close to the tympanic membrane.

FIG. 7is an end view of an exemplary earmold, such as earmolds102or302. The first microphone opening10is arranged in the second surface22(earmold102) or in the microphone tube (earmold302). The receiver opening14is arranged in the first surface20of the earmold shell4being the tip surface7. The vent opening18is arranged in the third surface24of the earmold shell4. The first transverse distance d′1between the first microphone opening10and the receiver opening14is 2 mm. The second transverse distance d′2between the first microphone opening10and the vent opening18is 2 mm. The third transverse distance d′3between the receiver opening14and the vent opening18is 4 mm.

FIG. 8illustrates an exemplary earmold402. The earmold402comprises a receiver tube36extending from the second surface22of the earmold shell4with the receiver opening14formed at a distal end of the receiver tube36. In the earmold, the first microphone opening10may be arranged in a microphone tube extending from the tip surface7.

FIG. 9is an exemplary end view of earmold402. The first microphone opening10is arranged in the first surface20of the earmold shell4being the tip surface7. The receiver opening14is arranged in the receiver tube extending from the second surface22of the earmold shell4, and the vent opening18is arranged in the third surface24of the earmold shell4. The transverse distance between the first microphone opening10and the receiver opening14is 2 mm. The transverse distance between the first microphone opening10and the vent opening18is 4 mm. The transverse distance between the receiver opening14and the vent opening18is 2 mm.

Characteristics of exemplary earmolds A-E are set out in the table below, where d1is the first distance, d2is the second distance, d3is the third distance, d′1is the transverse distance between the first microphone opening and the receiver opening, d′2is the transverse distance between the first microphone opening and the vent opening, and d′3is the transverse distance between the receiver opening and the vent opening.

LIST OF REFERENCES