Behind-the-ear hearing aid

This invention concerns a behind-the-ear hearing aid according to the preamble to claim

1

.

With these types of hearing aids, it is common to provide an on/off switch and, separately from it, another activating organ, for example for adjusting the amplification. This leads, especially when operating the applied hearing aid, to the problem of feeling around for the activating organ needed, not to mention that the activating organs provided take up substantial structural volume and providing the organs mentioned causes considerable complication of the hearing aid with the electrical connections to be provided, and also makes it more prone to problems.

The purpose of this-invention is to eliminate the disadvantages mentioned. For this purpose, the hearing aid in the invention has the features in claim

1

.

According to the invention, two categories of switching functions are combined on one and the same activating organ, namely, in the positions mentioned, preferably the ON/OFF switch of the hearing aid and, in a second activating direction, for example adjustment of amplification. This increases the user friendliness on one hand and makes it possible to differentiate by feel the two different types of activation on an activating switch, on the other hand. The single activating switch in the invention also takes up less structural volume and the hearing aid as a whole is simpler, because electrical connections to switching organs need be placed only in the area of an activating organ provided.

Providing only one mechanically activated organ also reduces its proneness to problems and if problems do occur, makes them much simpler to repair.

As mentioned, in one preferred form of embodiment, one of the positions is used as the on position of the hearing aid, the other as the off position, and the activating organ, when activated in the second direction, works as a toggle switch. In another preferred embodiment, the activating organ is tilt-mounted on a slide that can move basically linearly and has a contact that can be brought into contact with a fixed switching contact on the device by activating it in the second direction. This contact is preferably made of a flexible plastic, preferably shaped like a little hat, as is known from computer keyboard mats or remote-control keyboards. It is also preferred that the first activating direction of the activating organ lie basically in the direction of generating lines on the hearing aid body, preferably along outside curved generating lines, in relation to the flexure of the hearing aid body, and the second activating direction perpendicular to the walls of the body of the hearing aid.

The behind-the-ear hearing aid in the invention will now be explained using figures which show one embodiment of the behind-the-ear hearing aid preferred today.

FIG. 1

shows a simplified behind-the-ear hearing aid in the invention in a longitudinal section;

FIG. 2

shows a perspective view of the hearing aid in the invention;

FIG. 3

shows a perspective view of the preferred design of a battery compartment cover on the hearing aid in the invention;

FIG. 4

shows a top view of the cover in

FIG. 3

with parts with left-right ear coding;

FIG. 5

shows, on one hand, the basic housing of the device in the invention, and on the other hand, an added module that is provided or could be, in a perspective view;

FIG. 6

shows an enlarged view of the electric/acoustic transducer unit on the hearing aid in the invention according to

FIG. 1

;

FIG. 7

shows a simplified, schematic view of a preferred activating organ provided on the device in the invention and

FIG. 8

shows schematically the unit in

FIG. 6

to explain the acoustic couplings.

FIG. 1

shows a somewhat simplified longitudinal section of the behind-the-ear hearing aid in the invention as a whole, where the individual function blocks and function parts are first described. The hearing aid

1

includes a horn-shaped curved, tubular basic body with a central axis A, which has a connecting support

5

for a coupling tube leading into the ear on the thinner, uncurved end, as an acoustic output. The connecting supports

5

can be exchanged for a tube support

9

, which sits, is set on or screwed on a basic housing.

The inner channel

7

of the connecting support

5

continues through the tubular support

9

into a transmission channel

11

in the basic housing

3

. The transmission channel

11

in turn is coupled to an electric/acoustic transducer arrangement

15

in one compartment

13

of the basic housing

3

.

As can be seen from

FIG. 1

, the transmission channel

11

extends along the inner curve of the basic housing

3

in such a way that there is room for a microphone unit

17

on the outer curve. The basic housing

3

has a cover

19

molded into it in this area and in the area of the culmination point of the device is stopped by means of a plug axis

21

. As can be seen especially in

FIG. 2

, the cover

19

extends along generating line M of the device body, up into the area of the electric/acoustic transducer unit

15

, FIG.

1

. The microphone unit

17

is accessible when the folding cover

19

is removed and preferably makes electrical contact only on a flexprint strap (not shown), folded over the transmission channel

11

and is on a sound-input slot

23

.

When the cover

19

is closed, at least two holes in the microphone unit

17

are opposite an insert

25

in a slot

23

in the cover

19

. The insert

25

is acoustically “transparent” and has a large number of passages between the environment U and an equalization volume V, which latter is left free between the discreet microphone inlet openings (not shown) and said insert. Preferably the insert

25

is made of a sintered material, like especially sintered polyethylene and even more preferably coated so it is water-repellant. It also forms a grid fineness between 10 &mgr;m and 200 &mgr;m with an open porousness of preferably over 70%. Furthermore, the microphone unit

17

and the insert

25

are arranged in the slot

23

on the hearing aid

1

so that when the hearing aid is worn, they are exposed, if possible, to no dynamic air pressure from the environment U, by being positioned—as can be seen in FIG.

1

—in the area of the cup of the horn-shaped curved, tubular basic body. Especially when an acoustic/electric transducer with directional characteristics is made using at least the two spaced microphones mentioned, due to the intermediate volume V, in the sense of a “common model” suppression, different coupled equal acoustic signals along the insert

25

have a tendency to be compensated because of the equalizing effect of the volume V.

The insert

25

also protects against dirt and is easy to clean due to its preferred water-repellant coating.

Another advantage of the insert

25

with its large number of passages is—closely coupled with the aspect of the above-mentioned “common mode” suppression—that all kinds of dirt have the same effect on both microphones and there is therefore no worsening of the directional effect (directional characteristic), which is a central problem with conventional directional microphones with two and more discrete holes.

Please refer to EP-A-0 847 227 by the same applicant concerning this insert

25

and its effects.

After the electric/acoustic transducer arrangement

15

in the basic housing

3

, there is an electronic unit

27

, then a battery compartment

29

. On the outside of the basic housing, in the area between the battery compartment

29

and the electronic unit

27

, there is an activating switch

31

. The perspective view in

FIG. 2

clearly shows in particular the connecting supports

5

, the basic housing

3

, the cover

19

with the sound-input slot

23

and insert

25

, and the activating switch

31

.

Battery Compartment

A flat cylindrical battery or a correspondingly molded storage battery

33

is inserted into the battery compartment

29

in the end of the basic housing

3

, in such a way that the axis of the battery cylinder, with its front surfaces

33

u

and

33

o

, lies at least basically coaxial to the longitudinal axis A of the basic body.

On the base

30

of the battery compartment

29

, centered in axis A, there is a first spring contact

35

; a second

37

makes spring contact with the side of the battery

33

. The battery compartment

29

can be locked with a cover

39

that is transverse to axis A in the closed position and is swivel- or bayonet-mounted, at

41

, on the basic housing

3

or on the battery compartment

29

.

This transverse arrangement of the battery

33

on the hearing aid has major advantages: The surface closed by the cover

39

is relatively large and can be used further, as will be described later. Because the battery compartment cover

39

is arranged at the deepest place on the device and the cover impact points are transverse to the axis A to the basic housing

3

, penetration of sweat into the battery compartment is barely critical. Furthermore, with this battery compartment design, the contacts

37

and

35

inside the compartment are protected, and the cover

39

has no electrical contacts. Because the basically cylindrical space inside the basic body

3

is used up, there is practically no unused lost space.

FIG. 3

is a perspective view of one preferred form of embodiment of the battery compartment cover

39

, designed as a folding cover. With the snapping hinge part

43

, it can be unlatched from the swivel bearing

41

in FIG.

1

and locked. In one preferred form of embodiment, it also has a lock

45

, plus a spring catch

46

.

FIG.

4

.shows the cover

29

in

FIG. 1

in an outer view. The lock

45

can only be used from the outside with a tool, for example a screw driver and has a slot

49

on a rotating plate

47

for this. The plate

47

, which is built onto the folding cover

39

when the lock is mounted is specifically colored in two designs, for example red and blue, so that this part is also used as an indicator of whether the hearing aid in question is for the left or right ear.

As was mentioned, the embodiment of the battery compartment

29

shown, especially the fact that the flat battery cylinder is coaxial to axis A of the hearing aid, has another important advantage. The hearing aid shown in

FIG. 1

is a basic configuration.

There is often a desire to equip this basic configuration with more options, for example with an interface unit for wireless signal transmission of a programming plug-in unit, another audio input, a larger storage battery compartment, a mechanical activating unit, etc. For this, the battery compartment shown in

FIG. 1

is reconfigured as shown in FIG.

5

. The battery

33

is taken out of the compartment and instead of it, the plug-in part

34

of a corresponding extra module

51

is plugged in and makes electrical contact at the contact points

35

a

and

37

a

for the battery contacts.

To use such extra modules, it is always possible to provide other contacts in the compartment

29

.

The compartment

29

a

now acting as an actual battery compartment with battery

33

is now provided on the extra module

51

and, accordingly, the cover

39

, which is removed from the basic housing

3

, for example, and snapped onto the extra module or snapped on like a bayonet. If necessary, more such modules

51

can be stacked on the basic module of the hearing aid shown in FIG.

1

. The extra modules

51

are preferably attached with a snap-on part

43

a

provided on the modules

51

, similar to the hinged part

43

on the folding cover

39

, as well as a snapping part

46

a

similar to snapping part

46

on said folding cover

39

or, if there is a bayonet lock, by being pushed in, turned and locked.

Thus it is possible to give the hearing aid-the simplest modular design desired so that the battery or storage battery

33

is always accessible from the outside.

Electric/Acoustic Transducer Arrangement

FIG. 6

shows a simplified view of the design and mounting of the arrangement

15

mentioned on the basic housing

3

and in the view in FIG.

1

. Arrangement

15

includes, encapsulated in a loud-speaker housing

53

, the loud-speaker arrangement (not shown) with a loud-speaker membrane. Through coupling holes drawn schematically at

55

, the sound waves excited by the loud-speaker membrane from the space on the back of the membrane are coupled in the loud-speaker housing

53

in the surrounding space U

53

of the loud-speaker housing

53

. From the space on the front of the membrane, the acoustic signals—shown by arrow S—are coupled to the transmission channel visible in FIG.

1

.

The loud-speaker housing

53

is held on all sides in spring, preferably flexible rubber bearings

57

, basically free to oscillate. The relatively large space U

53

is defined by the bearings

57

between the outer wall of the loud-speaker housing and a capsule

59

, which leads to a substantial increase in the low tones. The resonance space on the back of the membrane is increased by a multiple by space U

53

. Capsule

59

and its holder

61

are sealed to make space U

53

acoustically effective to the full extent.

Thus, acoustically, the storage volume for the loud-speaker arrangement is optimally use. Capsule

59

also acts preferably as a magnetic shield housing and is preferably made of &mgr; metal for this. It is designed like a cup and hooked on holder

61

, which is designed as a plastic support. The spring, preferably flexible rubber bearings

57

mentioned are tensed between the capsule

59

, the holder

61

on one side and the loud-speaker housing

53

.

FIG. 8

shows the acoustic coupling explained purely in principle. The membrane

54

of the loud speaker in housing

53

defines in said housing a first space R

1

, which is coupled to the acoustic output of the hearing aid—shown by S—and a second R

2

, which is coupled via one or more holes

55

to space U

53

formed between the capsule

59

and the housing

53

.

Activating Switch

31

FIG. 7

shows a preferred form of embodiment of the activating switch

31

, simplified and schematically drawn. The activating switch

31

includes a tilt button

63

, which is mounted on one side at

65

so it can tilt.

The tilt mount

65

is molded on a slide

67

which—as shown by double arrow F—is mounted so it can move linearly in relation to the basic housing

3

. As shown schematically with the spring contact

69

fixed in relation to the basic housing

3

and the bridge contact

70

on the slide

67

, the device is turned on and off by the back and forth movement-of the slide via button

63

.

The slide

67

has a groove

72

going through it through which a contact pill

73

fixed in the housing

3

projects. This is covered by a spring contact part

75

arranged on the slide

67

, which is preferably made as a keyboard element of flexible, at least partially electrically conductive plastic, as is known for example from remote-control keyboards. When the tilt button

63

—as shown by double arrow K—is pushed, the contact part

75

comes in contact with the pill

73

and makes an electrical connection between these elements. Although for the expert there are a great many possible electrical connections, including a switching strip S

1

, activated by the slide movement F, and switching strip S

2

, activated by the tilting movement K of the tilt button

63

, preferably—as shown in dashes in FIG.

7

—the spring contact

69

is connected to the hearing aid battery

33

and the bridge contact

70

to contact part

75

, and thus the contact pill

73

works as an electrical output of the switching arrangement.

Thus, the activating switch

31

works both as an on/off switch and also, in the one position, as a toggle switch, which works—for example for fast individual amplification adjustment—in steps on the electronic unit

27

in FIG.

1

.

With the activating switch

31

, two functions are combined, a push switch and a toggle switch, a function melding that is highly advantageous especially for the behind-the-ear hearing aid in the invention. The operating difference ensures that there is no confusion in function, which is much more critical when two switches are provided for the two functions mentioned.

Design of Housing

3

As can be seen especially in

FIG. 5

, the basic housing

3

is made up of a curved, correspondingly molded unmachined part. In one preferred embodiment, this part

3

is designed in one piece, preferably of plastic and is not, as is otherwise usual in the design of such hearing aids, able to be separated into two shells along generating lines represented by M in FIG.

5

. Thus, occurs the assembly of the individual units in the basic housing

3

: they are simply inserted into the ear, which is much simpler than assembly on opened shells. Another advantage of a tubular, one-piece embodiment is its much greater stability compared to a divided housing. This permits a reduction in the housing wall strength and thus a reduction in the size of it, and with a given outer volume, an increase in the usable inner volume.

Advantages of Overall Configuration

Looking at

FIG. 1

, it can be seen, especially in the preferred one-piece design of the basic housing

3

, that the individual components, especially

11

,

15

,

27

,

29

and/or

51

, are assembled by axial sequential insertion into the basic housing

3

. The shaping of the housing

3

with corresponding guides ensures fast, precise positioning, and reciprocal electrical contact between the electrically operated units is solderless by means of spring contacting. Thus, the units to be provided can be tested out in advance and measured and assembled afterward with no fear of their being affected in any way. This assembly can definitely be automated. The overall housing with basic housing

3

and cover

19

, if necessary

39

, is provided with corresponding seals at the points of impact that make it simple to seal tight.

The preferred design of the electric/acoustic transducer arrangement

15

ensures optimum magnetic shielding of the loud speaker and optimal acoustic sealing in relation to body sounds.