Audio device comprising a microphone

Abstract

An audio device includes a microphone, a sound canal allowing sound to pass from the surroundings to the microphone, a signal path from the microphone to a receiver, and a current source, such that sounds received at the microphone may be enhanced and presented at the ear level of the user. A protection screen is provided at the sound canal, and includes a first surface which faces the surroundings and a second surface which faces the sound canal, and defines a slit-formed opening between the first surface and the second surface. The curvature between the first surface and the slit-formed opening is smooth and gradual, and a sharp edge is located at the transition between the second surface and the slit-formed opening.

Claims

.[.1. An audio device, comprising: an external casing; a microphone housed within the external casing, acoustically connected through a sound canal to an inlet port of the external casing; and a protective cover attached to the external casing above the inlet port, the protective cover including a first surface facing substantially toward exterior of the audio device, the first surface having a smooth curvature toward an elongated slit opening of the protective cover, and a second surface facing toward interior of the audio device, the second surface meeting the first surface along an edge defining the boundary of the elongated slit opening..].

.[.2. The audio device according to claim 1, wherein the edge has a cross-sectional angle of less than ninety degrees..].

.[.3. A protection screen for an audio device, comprising: a first surface facing substantially toward exterior of the audio device, the first surface having a smooth curvature toward an elongated slit opening; and a second surface facing toward interior of the audio device, the second surface meeting the first surface along an edge..].

.[.4. The protection screen for an audio device according to claim 3, wherein the audio device includes an exterior casing having at least one microphone inlet, and the elongated slit opening of the protection screen is positioned above the at least one microphone inlet..].

.[.5. A protection screen for an audio device, comprising: a first surface facing substantially toward exterior of the audio device, the first surface having a smooth curvature toward an elongated slit opening; and a second surface facing toward interior of the audio device, the second surface meeting the first surface along an edge, wherein the audio device includes an exterior casing having two microphone inlets, the elongated slit opening extends above the two microphone inlets, defining an open space between the protection screen and an upper surface of the casing between the two inlets..].

.[.6. The protection screen for an audio device according to claim 3, wherein the edge defines the boundary of the elongated slit opening..].

.[.7. The protection screen for an audio device according to claim 3, wherein the edge has a cross-sectional angle of less than ninety degrees..].

.[.8. An audio device, comprising: an external casing including two microphone inlets; at least one microphone housed within the external casing, acoustically connected through a sound canal to at least one of the two microphone inlets of the external casing; and a protective cover attached to the external casing above the two microphone inlets and defining an open space between itself and the external casing, the protective cover including a first surface facing substantially toward exterior of the audio device, the first surface having a smooth curvature toward an elongated slit opening of the protective cover, a second surface facing toward interior of the audio device, the second surface meeting the first surface along an edge defining the boundary of the elongated slit opening, and the elongated slit opening..].

.Iadd.9. An audio device, comprising: an external casing including a shell, a chassis shaped to fit into the shell, and a battery frame, the external casing being configured for placement behind an ear of a user and having a plurality of inlet ports; at least two microphones housed within the external casing, each microphone being acoustically connected through a respective sound canal to a respective inlet port of the external casing so as to receive sound from outside the external casing, each microphone being centered within the external casing; the shell, the chassis, and the battery frame being configured to enclose an audio processing device and a battery; and a protective cover attached to the external casing above the inlet ports, the protective cover including two elongated slit openings, the two elongated slit openings are positioned on opposite sides of center of the protective cover, a first surface facing substantially toward the exterior of the audio device, the first surface having smooth curvatures at a transition toward said two elongated slit openings of the protective cover, a second surface facing toward the interior of the audio device, the second surface meeting the first surface along edges defining the boundaries of the two elongated slit openings, and wherein, below the protective cover, the inlet ports lead through respective sound canals in the chassis to the two microphones, and a space beneath the two elongated slit openings is provided under the two elongated slit openings, such that sound may pass through each of the two elongated slit openings at any point and reach each of the microphones. .Iaddend.

.Iadd.10. The audio device according to claim 9, wherein the edges have a cross-sectional angle of less than ninety degrees. .Iaddend.

.Iadd.11. An audio device, comprising: a shell being configured for placement behind an ear of a user; a chassis shaped to fit into the shell; two microphones housed within the chassis, the microphones being centered within the chassis; and a protection screen attached to the chassis, the protection screen including, two elongated slit openings, the elongated slit openings being positioned on opposite sides of a center of the protection screen, a first surface facing substantially toward the exterior of the audio device, the first surface having smooth curvatures at a transition toward said two elongated slit openings, a second surface facing toward the interior of the audio device, the second surface meeting the first surface along edges, an intermediate part between the two elongated slit openings, a sound entrance, below the protection screen, acoustically connecting each of the two elongated slit openings with each of the respective microphones, and a space beneath the two elongated slit openings is provided along the entire length of the two elongated slit openings, such that sound may pass through each of the two elongated slit openings at any point and reach each of the microphones. .Iaddend.

.Iadd.12. The audio device according to claim 11, wherein the shell has at least one microphone inlet, and the two elongated slit openings of the protection screen are positioned above the at least one microphone inlet. .Iaddend.

.Iadd.13. The audio device according to claim 11, wherein the edges define the boundaries of said two elongated slit openings. .Iaddend.

.Iadd.14. The audio device according to claim 11, wherein the edges have a cross-sectional angle of less than ninety degrees. .Iaddend.

.Iadd.15. An audio device, comprising: an external casing including two microphone inlets, the external casing including a shell and a chassis, the external casing being configured for placement behind an ear of a user; at least two microphones housed within the external casing, acoustically connected through a sound canal to at least one of the two microphone inlets of the external casing; at least two sound canals allowing sound to pass to the microphones; a signal path from the microphones to a speaker, such that sounds received at the microphones is enhanced and presented at the ear of the user; a protective cover attached to the external casing above the two microphone inlets and defining an open space between itself and the external casing, the protective cover including an elongated slit opening, said elongated slit opening having a length measurement that is larger than a width measurement a first surface facing substantially toward the exterior of the audio device, the first surface having a smooth curvature at a transition toward said elongated slit opening of the protective cover, a second surface facing toward the interior of the audio device, the second surface meeting the first surface along an edge defining the boundary of the elongated slit opening, a space beneath the elongated slit opening provided along a length of the elongated slit opening, such that sound may pass through the elongated slit opening located at any point on the protective cover to reach each of the microphones; an aperture between the protective cover and the chassis; and a sound entrance below the aperture and above one of the microphones. .Iaddend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view along line A-A of an audio device with cover plate as shown in FIG. 3,

(2) FIG. 2 is a lengthwise sectional view of an audio device according to the invention, FIG. 3 is a side view,

(3) FIG. 4 is a perspective view of the detachable cover seen from below, and

(4) FIG. 5 is an exploded view of the main parts of the audio device.

DESCRIPTION OF A PREFERRED EMBODIMENT

(5) In the exploded view of FIG. 5 the various parts of the audio device are shown. A generally triangular shell part 20 forms the basis of the device. A chassis 14 is shaped to fit into the shell 20 from a first side and a battery frame 21 fits into a second side of the shell part. The three parts: shell 20, chassis 14 and battery frame 21 are shaped to enclose the electronic parts of the audio device, namely microphones 1, 11 seen in FIGS. 1, 2 and 3 and a print (not shown) with an audio processing device and a battery. Further, a socket 22 is provided for outputting an electric audio signal. A plug 23 fits the socket and leads inside a tube 24 are provided for powering an audio speaker 25. In use, the audio device is placed behind a user's ear, and the speaker 25 is placed inside the ear canal of the user to allow the user to hear enhanced versions of the sound received at the microphones 1,11. A windscreen 3 is further mountable on the chassis 14 to protect the sound entrances 2, 12.

(6) In FIG. 2 an embodiment of the invention is shown in section along a length axis of the audio device. FIG. 1 is a sectional view along line A-A of FIG. 3 and thus perpendicular to the view in FIGS. 2 and 3 is shown. As seen the protection screen 3 is provided over sound entrances 2, 12 and protects the entrances from direct impact of wind and other environmental influences. The screen 3 has two slit-formed openings 6 extending along the length of the screen 3 as best seen in FIGS. 1 and 4. The screen 3 has a first surface 4 facing the environment and a second surface 5 facing the inside of the audio device with microphones 1,11. The surface 4 is made even and smooth so that it will be easy to clean and so that no wind noise will result from air passing over the surface 4. Below the screen 3 the sound entrances 2,12 lead through respective canals in the chassis 14 to the microphones 1,11. The slit-formed openings 6 in the screen 3 are provided above furrows 15 in the chassis 14 and from the furrows 15 access is allowed to the sound entrances 2, 12 for the respective microphones 1,11. The furrows 15 and the slit-formed openings 6 together allow sound to reach the microphones 1, 11 from any point above the surface 4.

(7) As seen in FIG. 1 the microphones 1,11 are placed in the centreline of the audio device 10 and the furrows 15 and slit-formed openings 6 extend at each respective side of the centreline. Thus the sound entrances 2,12 are covered by an intermediate part 13 of the screen 3.

(8) Apertures 19 between the screen 3 and the chassis 14 are provided and are best seen in FIG. 1. The apertures 19 connect the furrows 15 at both sides with the sound entrances 2,12. Each sound entrance 2, 12 thus receive sound from both slit formed openings 6 along the paths indicated by arrows 26 in FIG. 1. The audio device will still function even if one of the slit-formed openings 6 becomes clogged.

(9) Resonance chambers 18 are provided in connection with each sound entrance 2,12, between the screen 3 and the chassis 14. As seen in FIG. 2 the chambers 18 are blind holes, and they will aid to dampen certain frequencies in the ultrasound range, and this will make the audio device less sensitive to the detrimental influences of ultrasound used in room sensors and automatic door openers.

(10) As seen in FIG. 1 the transition between the first surface 4 and the opening 6 is made with a smooth and rounded shoulder 7, whereas the transition between the second surface 5 and the opening 6 is made with a sharp edge 8. This ensures both that water is less likely to enter the slit-formed openings 6, and that the openings are easily cleaned by simply running a soft cloth along the length axis of the device. Tests have shown that water will form pearls or droplets on the shoulder 7 rather than enter the openings 6. This is due to the sharp edge 8 between the slit 6 and the second surface 5 and the rounded shape of the shoulder 7 in combination with the surface tension of water. A perfectly sharp edge between the surface 5 and the opening 6 is difficult to realize, and a rounded edge less than 0.05 mm is sufficiently sharp. Tests have further shown that the width of the slit-formed openings 6 should preferably be between 0.1 and 0.3 mm, and in a preferred embodiment the slit is 0.2 mm. This measure is taken at the narrow-most part of the slit. Further, it is important that the angle between the surface 5 and the side-walls of the slits 6 is less than 90 degrees in order that the overall profile of the slit-formed openings 6 becomes v-shaped. This helps to avoid clogging and allows easy cleaning of the wind screen.

(11) Wind noise is known to be a serious problem to especially hearing aid wearers, but through the shape of the screen 3 and the openings 6 and the arrangement of the microphones, it is ensured that wind noise is minimized, and at the same time the screen 3 provides good protection against other environmental influences like moisture and dust. As seen in FIG. 4 the screen has protrusions 17 that enable the screen to be mounted by click connections onto the chassis 14 of the audio device 10.