# Patent

## Title
Hearing aid having combined antennas

## Abstract

A hearing aid having a hearing aid housing, includes: a microphone; a processing unit configured to process an audio signal for compensating a hearing loss of a user; a battery provided closer to a second end of the hearing aid housing than to a first end of the hearing aid housing; one or more wireless communication units for wireless communication; at least a part of a first antenna for electromagnetic field emission and/or electromagnetic field reception, the at least a part of the first antenna being interconnected with one of the one or more wireless communication units; and a second antenna for electromagnetic field emission and/or electromagnetic field reception, the second antenna being interconnected with one of the one or more wireless communication units; wherein the second antenna is between a center axis of the battery and the second end of the hearing aid.

## Background
RELATED APPLICATION DATA
This application claims priority to and the benefit of Danish Patent Application No. PA 2015 70383, filed Jun. 22, 2015, pending, and European Patent Application No. 15001843.0, filed Jun. 22, 2015, pending. The entire disclosures of both of the above applications are expressly incorporated by reference herein.
TECHNICAL FIELD
The present disclosure relates to antennas for hearing aids, in particular the present disclosure relates to hearing aids having two or more antennas, such as for example to a hearing aid having a combination of an electrical antenna and a magnetic antenna. The hearing aid may be used in a binaural hearing aid system. During operation, the hearing aid is worn at the ear of a user.
BACKGROUND
Hearing aids are very small and delicate devices and comprise many electronic and metallic components contained in a housing small enough to fit in the ear canal of a human or be located behind the outer ear. The many electronic and metallic components in combination with the small size of the hearing aid housing impose high design constraints on radio frequency antennas to be used in hearing aids with wireless communication capabilities.
Moreover, the antenna in the hearing aid has to be designed to achieve a satisfactory performance despite these limitations and other high design constraints imposed by the size of the hearing aid.
Still further, in binaural hearing aid systems, the requirements to the quality of the communication between the hearing aids in the binaural hearing aid system are ever increasing, and include demands for low latency and low noise, increasing the requests for effective antennas in the hearing aids.
SUMMARY
It is an object to provide a hearing aid with improved wireless communication capabilities, such as improved wireless communication capabilities between two hearing aids worn at opposite ears of the user, and/or between a hearing aid and an accessory device.
In accordance with one or more embodiments, the above-mentioned and other objects are obtained by a hearing aid, the hearing aid having a hearing aid housing, the hearing aid housing having a first end and a second end and comprising a microphone configured to receive an audio signal, a processing unit configured to process the audio signal for compensating a hearing loss of a user, a speaker for providing the processed audio signal to the user, a battery, one or more wireless communication units for wireless communication, a first antenna for emission and/or reception of an electromagnetic field being interconnected with one of the one or more wireless communication units, and a second antenna for emission and/or reception of an electromagnetic field being interconnected with one of the one or more wireless communication units.
The battery may be provided closer to a second end of the hearing aid than to a first end of the hearing aid, and the second antenna may be provided between the battery, such as between a center axis of the battery, and the second end of the hearing aid. The first antenna may be provided between the battery, such as between the center axis of the battery, and the first end of the hearing.
It is an advantage of the hearing aid that a first antenna and a second antenna are provided in the hearing aid, increasing the wireless communication capabilities of the hearing aid.
According to a further aspect of one or more embodiments, a binaural hearing aid system is disclosed, the binaural hearing aid system comprising a first and a second hearing aid to be provided at a first and a second ear of the user, respectively, and wherein one or both of the hearing aids is a hearing aid as herein disclosed.
The first antenna may be configured for radiation in a first frequency range, and the second antenna may be configured for radiation in a second frequency range.
The first antenna may be provided on a first side of the battery and the second antenna may be provided on a second side of the battery, the first side of the battery and the second side of the battery may be opposite sides of the battery, either transversely or longitudinally. The first antenna may be provided between the battery and the first end of the hearing aid.
In one or more embodiments, the hearing aid comprises hearing aid electronic components including the signal processor. The hearing aid electronic components may be provided on a printed circuit board, and typically, the hearing aid electronic components are provided on the first side of the battery, such as between the battery and the first end of the hearing aid. Hereby, the battery provides shielding for the second antenna with respect to any noise caused by the first antenna and/or the hearing aid electronic components. Thus, the battery may act as a shielding element for the second antenna.
The hearing aid may be any hearing aid, such as a hearing aid of the in-the-ear type, such as in-the-canal type, such as completely-in-the-canal type of hearing aid, etc., a hearing aid of the behind-the-ear type, of the receiver-in-the-ear type of hearing aid, etc.
Typically, the hearing aid comprises a hearing aid part configured to be positioned behind the ear of a user and a coupling element for coupling sound or audio to the ear of a user.
In one or more embodiments, the hearing aid comprises a first hearing aid part configured to be positioned behind the ear of a user, a second hearing aid part being configured to be positioned in the ear of a user, and a coupling element coupling the first hearing aid part and the second hearing aid part. The first hearing aid part may comprise the battery, and the second hearing aid part may comprise the speaker. Typically, the first hearing aid part comprises at least the microphone, the processing unit configured to process the audio signal for compensating a hearing loss of a user and the battery, whereas the speaker may be provided in the second hearing aid part. Typically, also the one or more wireless communication units are provided in the first hearing aid part. The first hearing aid part may be provided in a first hearing aid housing, and the second hearing aid part may be provided in a second hearing aid housing. Such hearing aids are typically referred to as receiver-in-the-ear hearing aids or RIE hearing aids.
In one or more embodiments, the hearing aid comprises a first hearing aid part configured to be positioned behind the ear of a user and a coupling element, coupling the first hearing aid part and the ear canal of a user. Such hearing aids are typically referred to as behind-the-ear hearing aids, or BTE hearing aids.
The coupling element may provide a processed sound to the ear, or the ear canal, of a user. The coupling element may comprise an electrical connection to a second hearing aid part comprising a speaker or a receiver for receiving processed audio signals from the signal processor provided in the first hearing aid part. The coupling element may comprise a sound tube or a thin tube for providing processed sound to the ear. The coupling element may comprise an ear hook for providing the processed sound to the ear of a user.
In one or more embodiments, the coupling element may comprise at least a part of the first antenna. Thus, the first antenna may have at least a part of the antenna extending in the coupling element, and the antenna may have another part in the first hearing aid part and/or a further part in the second hearing aid part.
In some embodiments however, the first antenna and the second antenna are provided within the first hearing aid part, such as within the first hearing aid housing. In other embodiments, the first antenna may protrude into the coupling element.
A hearing aid housing, such as the first and/or second hearing aid housing, may comprise a hearing aid assembly, comprising components of the hearing aid, the hearing aid assembly being provided in the hearing aid housing. The hearing aid housing typically comprises a shell, such as a polymer or plastic shell, in a shape configured to be provided in the ear, in the ear-canal or behind the ear of a user. The coupling element is typically attachable to the hearing aid housing.
The one or more wireless communications unit(s) are configured for wireless data communication, and in this respect interconnected with the first and/or second antenna for emission and reception of an electromagnetic field. Each of the one or more wireless communication unit may comprise a transmitter, a receiver, a transmitter-receiver pair, such as a transceiver, a radio unit, etc. The one or more wireless communication units may be configured for communication using any protocol as known for a person skilled in the art, including Bluetooth, WLAN standards, manufacture specific protocols, such as tailored proximity antenna protocols, such as proprietary protocols, such as low-power wireless communication protocols, RF communication protocols, magnetic induction protocols, etc. The one or more wireless communication units may be configured for communication using same communication protocols, or same type of communication protocols, or the one or more wireless communication units may be configured for communication using different communication protocols.
In one or more embodiments, the first antenna has a longitudinal extension in a first direction. Thus, the first antenna may have an overall longitudinal extension in a first direction. The direction may indicate a line or path along which the first antenna is extending. For example, the overall length of the first antenna may be larger than the overall width of the first antenna indicating a longitudinal extension in the lengthwise direction.
The first antenna may extend in one or more primary planes, such as extend substantially in a primary plane, such that for example at least 95%, 90%, 85% or 80% of the first antenna extends in one or more of the primary planes. The one or more primary planes may be parallel primary planes.
Thus, for example, the first antenna may comprise a first antenna element extending along a first side of the hearing aid housing and a second antenna element extending along a second side of the hearing aid housing.
The first side of the hearing aid housing may be a first longitudinal side of the hearing aid housing, and the second side of the hearing aid housing may be a second longitudinal side of the hearing aid housing. The first side may be opposite the second side.
In one or more embodiments, the second antenna may have a longitudinal extension in a second direction, the second direction being parallel to, or being 0/180 degrees+/−35 degrees, to an ear-to-ear axis of a user, when the hearing aid is worn in its operational position during use.
The second direction may be orthogonal, such as 90 degrees+/−35 degrees, to at least one of the primary planes, such as orthogonal, such as 90 degrees+/−35 degrees, to one or more parallel primary planes.
In one or more embodiments, the second direction is a direction which is 90 degrees+/−35 degrees with respect to a side of the hearing aid, wherein the side is adjacent a head of a user during use.
Thus, for example, the first antenna may substantially extend in a primary plane, whereas the second antenna may extend in a second direction being orthogonal to the primary plane.
The first antenna may have a longitudinal extension in a first direction, whereas the second antenna may extend in a second direction being orthogonal to the first direction.
In one or more embodiments, the first antenna is configured to have a first radiation pattern and the second antenna is configured to have a second radiation pattern, the first radiation pattern being different from the second radiation pattern.
The near field pattern for the first and/or the second antenna may be a TM polarized near field. The first and/or second radiation pattern may be dominated by the E-field, so that a primary part of the overall electromagnetic field, such as more than 75%, such as more than 80%, such as more than 85%, such as more than 90% of the overall electromagnetic field, is contributed by the E-field.
An advantage of the hearing aids as disclosed herein is that an improved wireless ear-to-ear communication may be achieved for most head sizes, shapes and amount of hair may be provided. Human heads and human ears vary in size and shape and also the amount of hair varies from person to person, and thus. Hearing aids adapted for wireless communications may be susceptible to impairments of for example the ear-to-ear communication due to e.g. the head of the user. Radio waves from a hearing aid at one side may have to travel through or around the head in order to reach the hearing aid at the other ear. Therefore, the human head may be perceived as an obstacle to the ear-to-ear communication. It is an advantage that the antennas as provided in the hearing aids improve the ear-to-ear communication.
In one or more embodiments, the first antenna is configured to operate in a first frequency range, and the second antenna is configured to operate in a second frequency range. The first frequency range may comprise higher frequencies than the second frequency range.
The first antenna may be an electric antenna, and the second antenna may be a magnetic antenna.
The first antenna may be configured to operate in a first frequency range, such as at a frequency above 800 MHz, such as at a frequency above 1 GHz, such as at a frequency of 2.4 GHz, such as at a frequency between 1.5 GHz and 3 GHz, during use. Thus, the first antenna may be configured for operation in ISM frequency band. The first antenna may be any antenna capable of operating at these frequencies, and the first antenna may be a resonant antenna, such as monopole antenna, such as a dipole antenna, etc. The resonant antenna may have a length of lambda/4 or any multiple thereof, lambda being the wavelength corresponding to the emitted electromagnetic field.
The second antenna may be configured to operate at a second frequency range, such as at a frequency below 100 MHz, such as at below 30 MHz, such as below 15 MHz, during use. The second antenna may be configured to operate at a frequency range between 1 MHz and 100 MHz, such as between 1 MHz and 15 MHz, such as between 1 MHz and 30 MHz, such as between 5 MHz and 30 MHz, such as between 5 MHz and 15 MHz, such as between 10 MHz and 11 MHz, such as between 10.2 MHz and 11 MHz.
Especially, for a second antenna operating at a frequency below 10 MHz or below 100 MHz, is it advantageous that the battery is provided between the second antenna and the hearing aid electronic components, as the second antenna operating at such frequencies could be susceptible to noise originating from the hearing aid electronic components.
In present day communication systems, numerous different communication systems communicate at or about 2.4 GHz, and thus there is also a significant noise in the frequency range at or about 2.4 GHz. It is an advantage that for some applications for which the noise may be acceptable, for example for data communication, a first antenna, such as a first electrical antenna may be used. For other applications, in which a high noise level may impact the transmission significantly, a second antenna, such as a magnetic antenna may be used. For example, the second antenna may be used for streaming of audio.
In one or more embodiments, the first antenna is configured for data communication at a first bit rate. In one or more embodiments, the second antenna is configured for data communication at a second bit rate, the second bit rate being larger than the first bit rate, such as by a factor 10, such as by a factor 30, a factor 50, a factor 100, etc.
The second antenna may be configured for communication using magnetic induction. It is an advantage of using magnetic induction that typically low latency may be obtained. Especially when streaming audio is it of importance to keep the latency low, to avoid delays noticeable by a user. Typically, a delay of less than 100 ms, such as of less than 50 ms, such as of less than 25 ms, such as of less than 10 ms, such as of less than 5 ms, such as of less than 1 ms, is preferred.
It is a further advantage of using magnetic induction for example for communicating between a first hearing aid and a second hearing aid in a binaural system that for the low frequencies, i.e. typically below 100 MHz, and corresponding long wavelengths, the head is not considered as a significant obstacle for the electromagnetic radiation emitted by the second antenna, thus, the reduction of electromagnetic radiation due to tissue absorption is reduced when the frequency is reduced.
A hearing aid having a hearing aid housing, the hearing aid housing having a first end and a second end, the hearing aid includes: a microphone configured to receive an audio signal; a processing unit configured to process the audio signal for compensating a hearing loss of a user; a battery provided closer to the second end of the hearing aid housing than to the first end of the hearing aid housing; one or more wireless communication units for wireless communication; at least a part of a first antenna for electromagnetic field emission and/or electromagnetic field reception, the at least a part of the first antenna being interconnected with one of the one or more wireless communication units; and a second antenna for electromagnetic field emission and/or electromagnetic field reception, the second antenna being interconnected with one of the one or more wireless communication units; wherein the second antenna is between a center axis of the battery and the second end of the hearing aid.
Optionally, the hearing further includes: a first hearing aid part configured to be positioned in the hearing aid housing behind an ear of the user; a second hearing aid part configured to be positioned in the ear of the user; and a coupling element coupling the first hearing aid part and the second hearing aid part.
Optionally, the first hearing aid part comprises the battery, and wherein the second hearing aid part comprises a speaker.
Optionally, the coupling element comprises at least a part of the first antenna.
Optionally, the second antenna has a longitudinal extension in a direction.
Optionally, the first antenna is in one or more planes, the one or more planes being 90°+/−35°, with respect to the direction.
Optionally, the first antenna is configured for radiation in a first frequency range, and the second antenna is configured for radiation in a second frequency range.
Optionally, the first antenna is an electric antenna and the second antenna is a magnetic antenna.
Optionally, the first antenna is configured to operate at a frequency above 800 MHz during use.
Optionally, the second antenna is configured to operate at a frequency below 100 MHz during use.
Optionally, the second antenna is configured to operate at a frequency anywhere between 1 MHz and 100 MHz.
Optionally, the first antenna is configured for data communication at a first bit rate.
Optionally, the second antenna is configured for data communication at a second bit rate, the second bit rate being larger than the first bit rate.
A binaural hearing aid system comprising a first hearing aid and a second hearing aid to be provided at a first ear and a second ear of a user, respectively, wherein at least one of the first and second hearing aids is the hearing aid.
In the following the embodiments is described primarily with reference to a hearing aid, such as a binaural hearing aid. It is however envisaged that the disclosed features and embodiments may be used in combination with any aspect of the embodiments.



BRIEF DESCRIPTION OF THE DRAWING
The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
FIG. 1 shows a schematic view of a hearing aid according to an embodiment of the disclosure,
FIG. 2 shows a BTE hearing aid with an ear hook according to the present disclosure,
FIG. 3 shows a RIE hearing aid according to the present disclosure,
FIGS. 4a and 4b show schematically components of a hearing aid according to the present disclosure,
FIG. 5 shows a three dimensional illustration of a hearing aid according to the present disclosure, and
FIG. 6 illustrates a shadow effect of the battery.



DETAILED DESCRIPTION
Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings.
Various embodiments are described hereinafter with reference to the figures. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated.
As used herein, the term “antenna” refers to an electrical or magnetic device which converts electric or magnetic power into radio waves. An electric antenna may comprise an electrically conductive material connected to e.g. a wireless communications unit, such as a radio chip, a receiver or a transmitter. A magnetic antenna, such as a magnetic loop antenna, may comprise a coil of electrically conductive material wound around a core of magnetic material.
FIG. 1 shows a block-diagram of a hearing aid. In FIG. 1, the hearing aid 10 comprises a microphone 11 for receiving incoming sound and converting it into an audio signal, i.e. a first audio signal. The first audio signal is provided to a signal processor 12 for processing the first audio signal into a second audio signal compensating a hearing loss of a user of the hearing aid. A receiver 13 is connected to an output of the signal processor 12 for converting the second audio signal into an output sound signal, e.g. a signal modified to compensate for a user's hearing impairment, and provides the output sound to a speaker 13. Thus, the hearing instrument signal processor 12 may comprise elements such as amplifiers, compressors and noise reduction systems etc. The hearing aid may further have a feedback loop for optimizing the output signal. The hearing aid has one or more wireless communication units 14, 16 (e.g. a transceiver) for wireless communication, each interconnected with an antenna 15, 17 for emission and reception of an electromagnetic field. The wireless communication units 14, 16 may connect to the hearing aid signal processor 12 and antennas 15, 17 for communicating with external devices, or with another hearing aid, located at another ear, in a binaural hearing aid system. The signal processor 12, the one or more wireless communication units 14, 16, and the antennas 15, 17 may be provided in a hearing aid housing 18. In some embodiments, the speaker 13 is provided in the first hearing aid part in the hearing aid housing 18, such as in behind-the-ear (BTE) hearing aids. In other embodiments, the speaker 13 is provided in a second hearing aid part 19, and for example provided in the ear of a user, such as in receiver-in-the-ear (RIE) hearing aids.
In FIG. 2, a hearing aid 10 is shown, the hearing aid 10 being configured to be positioned behind the ear of a user during use. The hearing aid 10 is a behind-the-ear hearing aid. The hearing aid 10 comprises a hearing aid housing 18 and a coupling element 20. In FIG. 2, the speaker 13 (not shown in FIG. 2) is positioned in the hearing aid housing 18, and the coupling element 20 couples the sound to the ear of a user. The hearing aid further comprises a battery 22 for supplying power to the electronic components, including the one or more wireless communication units 14, 16, the signal processor 12, etc., of the hearing aid. It is seen that the battery 22 is provided closer to a second end 26 of the hearing aid housing 18 than to a first end 24 of the hearing aid housing 18. The hearing aid furthermore comprises a first antenna 15 and a second antenna 17.
In FIG. 2, the first antenna 15 is provided within the hearing aid housing 18. It is however envisaged that the first antenna in some embodiments may extend into the coupling element 20. The first antenna 15 is an electric antenna, such as a monopole or dipole electric antenna. The first antenna 15 may be provided on a printed circuit board 28, and the printed circuit board 28 may be a flexible printed circuit board 28. Further electronic components may be provided on the printed circuit board 28.
The second antenna 17 is provided or positioned between the battery and a second end, such as between a center axis 21 of the battery 22 and the second end 26 of the hearing aid. Typically, the second antenna 17 is a magnetic antenna for establishing an inductive connection, and the second antenna may be a loop antenna, such as a magnetic loop antenna, a coil antenna, etc.
In some embodiments, the battery is a round flat type battery, such as a button cell type battery or coin cell type battery, and the center axis of the battery is an axis through a center of the battery from a first flat side of the battery to the other flat side of the battery. In some embodiments, a further battery axis 27 is defined as an axis through the center of the battery and a point on the circumference of the battery, the further battery axis being orthogonal, such as 90 degrees+/−15 degrees, such as 90 degrees+/−35 degrees, to a top side and/or a bottom side of the hearing aid housing 18 at the position of the center of the battery.
The battery may be a round flat battery, such as a coin cell type battery type, and the battery may be provided with the flat sides along longitudinal axes of the hearing aid housing 18, such as along the longitudinal axes of the first hearing aid part 33.
The second antenna 17 may be provided so that both the center axis 21 of the battery and the further battery axis 27 is on one side of the second antenna 17, and the second end 26 of the hearing aid housing 33, i.e. the first part of the hearing aid housing 33, is on another side of the second antenna 17. Thus, the second antenna 17 may be positioned between a center plane of the battery, the center plane being established by the center axis 21 of the battery and the further battery axis 27, and the second end 26 of the hearing aid housing 33.
It has been found that hereby, a shadow effect of the battery reduces interference between the first antenna 15 and the second antenna 17.
In FIG. 3, another hearing aid 30 is shown. In FIG. 3, like numerals represents the same elements as shown in FIG. 2. However, in FIG. 3, the hearing aid is a hearing aid having a first hearing aid part 33 being configured to be positioned behind the ear of a user, and a second hearing aid part 31 being configured to be positioned in the ear canal of a user. A coupling element 20 connects the first hearing aid part 33′ and the second hearing aid part 31. The hearing aid part 31 is shown as provided in housing or shell 31. In FIG. 3, a first part 15a of the first antenna 15 is provided in the first hearing aid part 33, and thus in the first hearing aid housing 33, while another part 15b of the first antenna 15 is provided in the coupling element 20. The first part 15a of the first antenna 15 is connected to a first wireless communication unit, such as a transceiver (not shown in FIG. 3) in the first hearing aid part 33.
The second antenna 17 is typically connected to a second wireless communication unit, such as a transceiver, different from the first wireless communication unit.
FIGS. 4a and 4b show schematically a hearing aid according to the present disclosure. FIG. 4a shows a side view of a hearing aid, such as of a first part 41 of a hearing aid 40. The first part of the hearing aid, i.e. the first hearing aid housing or part 41, has a longitudinal side 44 and a top side 49. The first hearing aid part 41 has a first end 24 and a second end 26. The hearing aid 40 has a battery 42, a first antenna 45 and a second antenna 47. It is seen that the battery is provided in the first hearing aid part 41 closer to the second end 26 of the first part 41 of the hearing aid, than to the first end 26 of the first hearing aid part 41. Thus, a first distance 2 from the second end 26 to the center axis 43 of the battery is smaller than a second distance 4 from the first end 24 to the center axis 43 of the battery.
The first antenna 45 extends along a side, such as a longitudinal side 44, of the first hearing aid part, or hearing aid housing, 41. The second antenna 47 is a magnetic loop antenna which has a longitudinal axis 46 out of the plane of the paper. It is seen that the center axis 43 of the battery 42 is out of the plane of the paper and thus parallel, such as parallel +/−15 degrees, such as parallel +/−35 degrees, with the longitudinal axis 46 of the magnetic loop antenna 47.
The further battery axis 48 is seen as being orthogonal to the top side 49 of the first hearing aid housing 41, such as having an angle of 90 degrees+/−15 degrees, such as 90 degrees+/−35 degrees, to a top side and/or a bottom side of the hearing aid housing 41 at the position of the center of the battery.
In FIG. 4b, the hearing aid 40 is seen from an end view, from the second end 26 of the first hearing aid housing 41. The hearing aid housing 41 has an end side 43 of the housing or shell of the hearing aid housing 41. The battery 22 is seen to be positioned closer to the second end 26 than to the first end (not shown in FIG. 4b) and the second antenna 47 is positioned between the second end 26 and the battery 22. Typically, the second antenna 47 comprises a magnetic core 38, in the form of a rod of a magnetic material, and windings 39 of an electrical conductor wound around the magnetic core 38. The magnetic core has a longitudinal axis 5.
The second antenna 47 may be provided so that the rod 38 of magnetic material is provided transversal in the first hearing aid housing 41, thus so that the second antenna has a longitudinal direction orthogonal to longitudinal sides 44 of the first hearing aid housing. The longitudinal axis 5 may thus form an angle with the longitudinal sides of the first hearing aid housing of 90 degrees, such as of 90 degrees+/−15 degrees, such as of 90 degrees+/−35 degrees. The second antenna 47 may primarily radiate through end surfaces 42. The magnetic core 38 and the windings 39 may be provided in a housing (not shown), such as a housing shielding longitudinal parts of the second antenna 47.
FIG. 5 shows schematically a 3-dimensional hearing aid. The first antenna 15 is provided on a PCB 28 in the top of a first hearing aid housing 18. The first antenna is connected to a transceiver or radio 14. The battery 22 is provided closer to the second end 26 of the hearing aid housing 18 than to the first end of the hearing aid housing 24. It is seen that the second antenna 17 is provided behind the battery with respect to the first antenna 15, and thus between the battery 22 and the second end 26 of the hearing aid housing. Coupling element 20 connects the hearing aid housing 18 to the ear of the user (not shown), either by coupling sound through a coupling element in the form of an ear hook or a sound tube, or by coupling a signal to a receiver as positioned in the ear of a user via a coupling element 20 comprising an electrical signal path.
FIG. 6 shows schematically a shadow effect of the battery as provided in the first hearing aid part, such as in the first hearing aid housing. In FIG. 6, the battery 22 is shown having a center axis 21 out of the plane of the paper and a further battery axis 48, as previously described. At one side of the battery, an antenna will be shielded by the battery from influence from an antenna at the other side of the battery. Thus, if the second antenna 17 is provided behind the battery 22, for example in the shadow region 61, the second antenna 17 is shielded from the first antenna 15 by the battery 22.
The shadow region 61 behind the battery may be defined as the region behind the center axis 21 of the battery 22, and more specifically, the shadow region may be defined as being the region behind the plane defined by the center axis 21 and the further battery axis 48. The shadow region 61 may be still further specified. Thus, an axis 62, 62′ may be defined as an axis having an angle 63 to the further battery axis 48 towards the first antenna 15, the angle 63 being between 0 and 45 degrees. At the intersection between the axis 62, 62′ and the circumference of the battery, a tangent is provided, and the shadow region is defined by the plane defined by the center axis 21 and the further battery axis 48, and furthermore, by the plane of the tangents 64, 64′. A second antenna 17 provided in the shadow region 61 may thus be shielded with respect to the antenna 15 provided at the other side of the battery, opposite the shadow region 61.
Although particular embodiments have been shown and described, it will be understood that it is not intended to limit the claimed inventions to the preferred embodiments, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the claimed inventions. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed inventions are intended to cover alternatives, modifications, and equivalents.

## Claims

1. A hearing aid having a hearing aid housing, the hearing aid housing having a first end and a second end, the hearing aid comprising:
a microphone configured to receive an audio signal;
a processing unit configured to process the audio signal for compensating a hearing loss of a user;
a battery provided closer to the second end of the hearing aid housing than to the first end of the hearing aid housing;
one or more wireless communication units for wireless communication;
a first antenna, at least a part of the first antenna for electromagnetic field emission and/or electromagnetic field reception, the at least a part of the first antenna being interconnected with one of the one or more wireless communication units; and
a second antenna for electromagnetic field emission and/or electromagnetic field reception, the second antenna being interconnected with one of the one or more wireless communication units;
wherein the hearing aid housing is configured for accommodation of the microphone, the processing unit, and the one or more wireless communication units; and
wherein the second antenna is located between a center axis of the battery and the second end of the hearing aid housing.

2. The hearing aid according to claim 1, further comprising:
a first hearing aid part configured to be positioned in the hearing aid housing behind an ear of the user;
a second hearing aid part configured to be positioned in the ear of the user; and
a coupling element coupling the first hearing aid part and the second hearing aid part.

3. The hearing aid according to claim 2, wherein the first hearing aid part comprises the battery, and wherein the second hearing aid part comprises a speaker.

4. The hearing aid according to claim 2, wherein the coupling element comprises at least a part of the first antenna.

5. The hearing aid according to claim 1, wherein the second antenna has a longitudinal extension in a direction.

6. The hearing aid according to claim 5, wherein the first antenna is in one or more planes, the one or more planes being at an angle that is anywhere from 55° to 125°, with respect to the direction.

7. The hearing aid according to claim 1, wherein the first antenna is configured for radiation in a first frequency range, and the second antenna is configured for radiation in a second frequency range.

8. The hearing aid according to claim 1, wherein the first antenna is an electric antenna and the second antenna is a magnetic antenna.

9. The hearing aid according to claim 1, wherein the first antenna is configured to operate at a frequency above 800 MHz during use.

10. The hearing aid according to claim 1, wherein the second antenna is configured to operate at a frequency below 100 MHz during use.

11. The hearing aid according to claim 1, wherein the second antenna is configured to operate at a frequency anywhere between 1 MHz and 100 MHz.

12. The hearing aid according to claim 1, wherein the first antenna is configured for data communication at a first bit rate.

13. The hearing aid according to claim 12, wherein the second antenna is configured for data communication at a second bit rate, the second bit rate being larger than the first bit rate.

14. A binaural hearing aid system comprising a first hearing aid and a second hearing aid to be provided at a first ear and a second ear of a user, respectively, wherein at least one of the first and second hearing aids is the hearing aid according to claim 1.