Miniature speaker and speaker cabinet and hearing aid

Abstract

A miniature speaker and speaker cabinet are provided, wherein the speaker is enclosed in an oblong capsule with a sound output opening at one end and leads passing from a speaker coil inside the capsule to connection points externally on the capsule, and where the cabinet encloses the capsule and at one end thereof comprise a lead input opening with leads passing there through to the connection points on the capsule, and where the cabinet further comprise a sound exit opening opposite the lead input opening, which is in fluid communication with the sound output opening of the capsule, wherein the cabinet has an internal space surpassing external measures of the capsule in all directions defining a gap between the capsule and cabinet wherein the thus defined gap is filled out with a hardening silicone.

Claims

1. A speaker and speaker cabinet assembly, comprising: a speaker enclosed in a capsule of oblong shape with a sound output opening at one end of the capsule and a cabinet enclosing the capsule, the cabinet including at one end thereof an input opening, and a sound exit opening opposite the input opening, which is in fluid communication with the sound output opening of the capsule, wherein the cabinet has internal space measures surpassing external space measures of the capsule in all directions defining a gap between an exterior surface of the capsule and an inner surface of the cabinet, the sound output opening of the capsule is surrounded by a gasket forming a seal between the inner surface of the cabinet and the sound opening, and the gap between the exterior surface of the capsule and the inner surface of the cabinet is filled with a hardening silicone, wherein internal space measures of the cabinet are no more than 10% larger than external space measures of the capsule.

2. The speaker according to claim 1, wherein the exterior surface of the capsule includes soft pads fastened to the capsule, and the soft pads center the capsule within the cabinet at least in a plane defined by a normal parallel to a center axis along the length of the capsule when the capsule is positioned inside the internal space of the cabinet.

3. The speaker according to claim 1, wherein the hardening silicone is a hardening silicone which shrinks during solidification.

4. The speaker according to claim 1, wherein the hardening silicone has a shrinking factor of around 30%.

5. The speaker according to claim 1, wherein the hardening silicone comprises a Shore A hardness of no more than 40.

6. A hearing aid, comprising: a casing part including an audio signal input device, a battery, a signal processor, and a speaker and a speaker cabinet, wherein the speaker is enclosed in a capsule of oblong shape with a sound output opening at one end of the capsule, the cabinet encloses the capsule, the cabinet including at one end thereof an input opening, and a sound exit opening opposite the input opening, which is in fluid communication with the sound output opening of the capsule, the cabinet has internal space measures surpassing external space measures of the capsule in all directions, defining a gap between an inner surface of the cabinet and an exterior surface of the capsule, the sound output opening of the capsule is surrounded by a gasket forming a seal between the inner surface of the cabinet and the sound opening, and the gap between the exterior surface of the capsule and the inner surface of the cabinet is filled with a hardening silicone, wherein internal space measures of the cabinet are no more than 10% larger than external space measures of the capsule.

7. The hearing aid according to claim 6, wherein the cabinet enclosing the speaker capsule comprises a snout defining the sound exit opening at a first end thereof with a flange surrounding the sound exit opening, and where the input opening at an opposed end thereof comprise an internal recess.

8. The hearing aid according to claim 7, wherein the cabinet is an assembly of a front part comprising the snout and sound exit opening and a rear part comprising the lead input opening, whereby the front part and rear part are glued to each other to form the casing.

9. The hearing aid according to claim 8, wherein a further opening is provided in the rear part where through the hardening silicone may be dispensed to fill out the gap between the speaker capsule and the inner walls of the cabinet.

10. The hearing aid according to claim 6, wherein the exterior surface of the capsule includes soft pads fastened to the capsule, and the soft pads center the capsule within the cabinet at least in a plane defined by a normal parallel to a center axis along the length of the capsule when the capsule is positioned inside the internal space of the cabinet.

11. The hearing aid according to claim 10, wherein the soft pads include soft flexible foam enabling an equal distance to any internal wall of the cabinet.

12. The hearing aid according to claim 6, wherein the audio signal input device is one of a microphone and an antenna.

13. The hearing aid according to claim 6, wherein the hardening silicone is a hardening silicone which shrinks during solidification.

14. The hearing aid according to claim 6, wherein the hardening silicone has a shrinking factor of around 30%.

15. The hearing aid according to claim 6, wherein the hardening silicone comprises a Shore A hardness of no more than 40.

16. A method for producing a hearing aid speaker unit, comprising: providing a speaker capsule of oblong shape holding a speaker coil, the capsule including a sound output opening at one end of the capsule; enclosing the capsule in a cabinet, the enclosing including inserting the capsule into a first cabinet part; placing a second cabinet part onto a portion of the capsule protruding from the first cabinet part; assembling the first and second cabinet parts to form an enclosure with the speaker capsule inside it, wherein the speaker capsule at least in a plane having a normal along the oblong axis of the capsule is seated in the cabinet with opposed gaps of equal size; and following said assembling, injecting a fluid silicone dampening medium through a hole in the cabinet to fill out the gap between the capsule and the cabinet.

17. The method according to claim 16, further comprising: centering the capsule within the first cabinet part at least in a plane defined by a normal parallel to a center axis along the length of the capsule during said inserting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view of a miniature speaker,

(2) FIG. 2 is a picture of the speaker with leads and a contact point in the shape of a jack adapted to be plugged into a hearing aid casing part,

(3) FIG. 3 shows is an enlarged sectional view of a part of the speaker cabinet and speaker capsule shown in FIG. 1,

(4) FIG. 4 is a schematic representation of a hearing aid,

(5) FIG. 5 is a computer-generated graphic representation of the two parts of a speaker cabinet,

(6) FIG. 6 shows a speaker cabinet with a hole in it for introduction of a hardenable silicone,

(7) FIGS. 7A-7D show examples of measure to ensure centered positioning of the speaker capsule within the cabinet.

(8) The figures are schematic and simplified for clarity, and they just show details which are essential to the understanding of the invention, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts.

(9) Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

DESCRIPTION OF A PREFERRED EMBODIMENT

(10) A miniature speaker 1 and speaker cabinet 2 are shown in FIG. 1. The speaker 1 is enclosed in an oblong capsule 3 with a sound output opening 4 at one end of the oblong capsule 3 and leads 5,6 passing from a speaker coil 7 inside the capsule 3 to connection points 8,9 externally on the capsule 3. As seen in the figure, the cabinet 2 encloses the capsule 3 and at one end of the cabinet 2 a lead input opening 10 with leads 11 passing there through to the connection points 8,9 on the capsule 3 are arranged. When the leads 11 are connected to an electrical audio output source, the electrical signals will reach the coil 7 and the speaker will provide an audio output in the form of sound waves by means of miniature components (not shown) namely a motor and a membrane connected to the motor as well known in speakers.

(11) The cabinet 2 also comprise a sound exit opening 12 opposite the lead input opening 10, which is in fluid communication with the sound outlet opening 4 of the capsule. The cabinet 2 has an internal space surpassing external measures of the capsule 3 in all directions and the thus defined gap 13 is filled out with a hardening silicone. Various types of silicones may be used, however it is recommended, that a silicone, which shrinks during solidification is used, as this will leave air filled voids, and during impact a better survival rate of the speaker is obtained, possibly due to the fact that the voids, which are filled with air or gas are highly compressible such that the silicone may easily deform under impact and need not flow as far as in the case where the entire gap is full of silicone. Preferably a silicone with a shrinking factor of around 30% is used. Further, a silicone type, which does not solidify entirely, has also shown some very good shock protection abilities, most likely due to enhanced flow properties of this material. The silicone should be a very soft type, such as having a Shore A hardness of no more than 40.

(12) The sound output opening 4 of the capsule 3 is surrounded by a gasket means 14 which forms a seal against an inside surface of the cabinet where said seal or gasket means surrounds the sound exit opening 4 of the cabinet 3. This measure ensures, that the silicon does not penetrate into the sound output opening 4 and possibly clog the mechanical parts of the speaker in the capsule 3, or flow into the sound exit opening 12 and thus prevent sounds from exiting the cabinet 2. This gasket means 14 may by any known type of gasketing or sealing, such as protrusions molded into the cabinet 2 or a soft o-ring provided on the receiver capsule similar well known means of sealing.

(13) As seen in FIG. 3 the speaker capsule 3 is centered inside the speaker cabinet 2, at least in a plane P defined by a normal parallel to a centre axis along the length of the oblong speaker capsule 3. By placing the capsule absolutely in the middle, it is ensured, that opposed gaps 13 will always be equal. This measure ensures that the gaps 13 are always at their maximum value and the best dampening is ensured. In the oblong direction of the speaker, the need for accuracy is not as pertinent, but never the less in this direction some measures must be taken to ensure, that the receiver capsule 3 is not at a foremost or rearmost position with respect to the cabinet 2.

(14) One possible way to ensure even spacing between the outer walls of the capsule and the inner walls of the cabinet are to use soft pads fastened to surface parts of the speaker capsule. This may ensure even distance between internal walls of the cabinet and the external walls of the capsule.

(15) FIG. 4 discloses in schematic form a hearing aid 20 having a casing part comprising audio signal input means such as a microphone 21 and/or an antenna 22, a battery 23, a signal processor 24 and output contact points 25 for serving an enhanced audio output signal. Leads 26 with a contact 29 attachable to the output contact points 25 at one end and at the other end thereof a miniature speaker and speaker cabinet 2 are also part of the hearing aid 20. The speaker and speaker cabinet comprise the element defined above and is only shown schematically in FIG. 4

(16) As further seen in FIG. 1 the cabinet 2 encloses the speaker capsule 3 and comprises a snout 27 defining the sound exit opening 12 at a first end thereof. The snout 27 has at an outer end thereof a flange 28 surrounding the sound exit opening 12. Further the lead input opening 10 at an opposed end thereof comprise an internal recess 30 (also visible in FIG. 7D. The flange 28 allows for an easy attachment of a dome to the snout 27 such that the cabinet 2 may be fixated at a predetermined location inside an ear canal, and the gap between the snot 27 and ear canal may be sealed off in controlled manner. The recess 30 at the opposed end will allow lead insulation means to be fixed to the cabinet 2 in a manner which prevents the user from inadvertently pulling the cabinet 2 away from the leads 11.

(17) As disclosed in FIG. 5 the cabinet comprises two parts, a front part 31 with the snout 27 and sound exit opening 12 and, a rear part 32 comprising the lead input opening 10. The two parts are glued together along glue lines 33 as seen in FIGS. 1, and 3.

(18) A further opening 35 is provided in the rear part 32 as seen in FIG. 6. Through this opening 35 the hardening silicone may be dispensed to fill out the gap 13 between the speaker capsule 3 and the inner walls of the cabinet 2.

(19) When a hearing aid of the above kind is to be produced, a hearing aid speaker unit comprising an oblong speaker capsule 3 is enclosed in a cabinet 2, in that a first cabinet part 31 and a second cabinet part 32 are initially assembled to form an enclosure with the speaker capsule 3 inside it. In doing this, the speaker capsule 3 is seated in the cabinet 2 with opposed gaps 13 of equal size at least in a plane having a normal along the length-axis of the oblong capsule 3. At last, following assembly of the cabinet parts 31,32 a fluid silicone dampening medium is introduced to fill out the gap 13.

(20) In FIG. 7D the speaker capsule comprises pads of soft flexible foam 38 enabling an equal distance to any internal wall part of the cabinet 2. In ensuring the equal size of the opposed gaps 13, a speaker capsule 3 having a square or rectangular shape in the mentioned plane is chosen as also seen from FIG. 7D, and flexible distance cushions 38 are initially attached to all four sides of the square or rectangular capsule 3. An adhesive may be used for this attachment.

(21) In FIG. 7A flexible bumps 40 are initially applied to surface parts of each of the four sides of the rectangular capsule 3. When inserted into the cabinet, the bumps will keep the capsule 3 well aligned.

(22) In FIG. 7B a flexible mesh 41 is shown on the speaker capsule 3, which is initially attached to at least all four sides of the speaker capsule 3. In the disclosed example it is a mesh comprising a soft silicone sheath with some parts covering the speaker capsule 3 and with openings in the sheath to expose other parts of the capsule. The mesh could be made very fine with densely set open and covered parts of the capsule.

(23) In FIG. 7C o-rings 42 are shown at the two ends of the capsule 3, which are initially attached either externally the speaker capsule 3 or internally to the two parts of the cabinet 2. Such o-rings 42 will ensure that the capsule 3 is placed with equal distance between the external wall parts of the capsule 3 and opposed internal wall parts of the cabinet 2.