Cap for microphone, and microphone for reducing pop and other wind noise

Abstract

A microphone cover for a microphone, and a microphone with a cover which facilitates at least substantially laminarised flow of wind and plosive sound past a microphone acoustic entry port. The cover is for an acoustic inlet port of a microphone, and includes a cap which includes a lower wall and an upper wall, a chord extending therebetween so the upper wall extends to a height of the chord above the lower wall, the upper and lower walls meeting at one or more peripheral edges. The body is for deflecting an airflow streamline incident on one of the one or more peripheral edges, so that a portion of it diverges and passes along the upper and lower walls to another peripheral edge; and a mount for mounting the aerofoil body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port. The body is configured to facilitate the laminarization of an airflow streamline incident on one of the one or more peripheral edges along at least lower wall to another peripheral edge.

Description

Cap for microphone, and microphone for reducing pop and other wind noiseTechnical Field

[0001] The present technology relates generally to microphones and recording sound; in particular, reducing extraneous wind and other pop and plosive noise while recording sound.Background

[0002] When recording sound outdoors, wind can interfere with the production of a clean sound recording. Even indoor recordings are impaired by plosives and pop, which include, at least in English, consonants and other explosive language elements which are formed by rapidly forcing air from the mouth. It may be important to achieve accurate reception of different types of voice timbre, sound signature, and / or an increased signal / noise ratio, and therefore it is no answer to move the microphone further away from the mouth of the person being recorded.

[0003] The plosives, pops and wind noises can completely drown out the other sounds in the signal. This is because the signal recorded by the microphone is clipped during the plosive or wind event and even for some time after, making the other sounds in the stream impossible to receive for unpredictable and lengthy periods.

[0004] A known way of reducing this pop and wind noise in a recorded signal is to cover a microphone entirely with a huge lump, sausage or sock constructed of foam and / or fur. This is done, for example, on a boom microphone, but, at least on an end of a long boom, this can be ungainly, heavy, and intrusive.

[0005] Many types of microphone are smaller, about palm sized, or smaller, such as those for holding in the palm of a hand or attaching to an item of clothing, and while users of these microphones demand a high quality response to plosives and pops, the form factor does not allow a big sock.

[0006] The present invention seeks to ameliorate one or more of the abovementioned disadvantages or at least provide a novel alternative to known pop and wind covers.Summary of Invention

[0007] Broadly, the present invention provides a microphone cover which facilitates at least substantially laminarised flow of wind and plosive sound incident on a microphone acoustic entry port.

[0008] In accordance with one aspect of the present invention there is provided a cover for an acoustic inlet port of a microphone, the cover including: a body including a lower wall and an upper wall, the upper and lower walls meeting at one or more peripheral edges, the aerofoil body being for deflecting an airflow streamline incident on one of the one or more peripheral edges, so that portions of the airflow pass along the upper and lower surfaces to another peripheral edge; and a mount for mounting the body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port.

[0009] In accordance with another aspect of the present invention there is provided a cover for an acoustic inlet port of a microphone, the cover including: a cap body including a lower wall and an upper wall which meet at one or more peripheral edges; and a mount for mounting the body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port.

[0010] The arrangement is such that the body or cap body is configured to deflect an airflow streamline incident on one of the one or more peripheral edges, so that a portion of it passes along the upper and lower surfaces, to another peripheral edge.

[0011] The arrangement is such that the body or cap body is configured to facilitate the laminarization of an airflow incident on one of the one or more peripheral edges along at least the lower surface.

[0012] In an embodiment the body or cap body is a flat plate.

[0013] In an embodiment the body or cap body is an aerofoil.

[0014] In an embodiment the body or cap body is a flat plate.

[0015] In an embodiment the body or cap body body is conical.

[0016] In an embodiment the body or cap body is frusto conical.

[0017] In an embodiment the body or cap body is pyramidal or frustopyramidal.

[0018] In an embodiment the cap body is rotationally symmetrical about a central vertical axis.

[0019] In an embodiment the cap body is unidirectional or multidirectional. That is, the body may have one leading edge and one trailing edge. Or, the cap body or aerofoil body may have a plurality of leading edges and a plurality of trailing edges. Or, the cap body or aerofoil body may have a plurality of leading edges leading to a centre.

[0020] In an embodiment the cap body is symmetrical.

[0021] In an embodiment the body is hollow.

[0022] In an embodiment the body is solid.

[0023] In an embodiment the upper and lower walls are smooth to facilitate attachment or laminarization of air flowing over them, rather than turbulent flow.

[0024] In an embodiment the body is a plastic. It may be ABS, PE, HDPE, or other polymers.

[0025] In an embodiment the body is a metal. In an embodiment the metal may be aluminium, steel, titanium, alloys of metals.

[0026] In an embodiment the body is additively formed such as by 3D printing.

[0027] In an embodiment the body is extruded or moulded or cast.

[0028] In an embodiment the body is machined.

[0029] In an embodiment the body or aerofoil body is rotationally symmetrical about a central vertical axis, or at least in three, four, five, six, seven, eight or so quadrants.

[0030] In an embodiment the body is a hump.

[0031] In an embodiment the body includes an upper wall which extends upwards from a peripheral edge, to a height of a chord, then extends downwards to another peripheral edge.

[0032] The arrangement in an embodiment is such that airflow incident on the body extends around the body, one path of part of the flow travelling a longer path than the other, so that the flow is laminarised as it passes along at least the lower wall and past or through the acoustic inlet port for the microphone.

[0033] In an embodiment the lower wall is 5.6mm wide.

[0034] In embodiments the lower wall may be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm wide, depending on the size of the acoustic entry port for the microphone.

[0035] In an embodiment the chord is about 2.85mm high, meaning the cap is 2.85mm high.

[0036] In embodiments the chord may be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm or 10mm, depending on the size of the microphone, the microphone unit and / or its acoustic entry port.

[0037] In an embodiment the port width is 2.45mm.

[0038] In an embodiment the port width may be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 9mm or 10mm depending on the size of the microphone, microphone type, microphone unit size and type.

[0039] In an embodiment the port depth is 2.25mm.

[0040] In an embodiment the port depth may be 1.5mm, 2mm, 3mm, 3.5mm, 4mm, 5mm, 6mm, depending on the microphone and microphone unit size and type.

[0041] In an embodiment the channel or laminarization zone height is 0.75mm.

[0042] In embodiments the channel or laminarization zone height is 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.4mm, 1.5mm, 1.75mm, 2mm, 2.5mm depending on microphone size and frequency attenuation response desired.

[0043] In an embodiment the body is at least a portion of a NACA wing profile.

[0044] In an embodiment the body includes a peripheral edge that is similar to a leading edge of a NACA wing profile.

[0045] In an embodiment the cover includes acoustic foam disposed around the periphery of the main body.

[0046] There may be mesh covering over cage wall openings. The mesh covering partially blocks wind but its acoustic impedance can be chosen to control the acoustic behaviour.

[0047] In an embodiment the cover includes a cage or frame to protect the main body and foam.

[0048] In an embodiment the cage includes peripheral frame elements and ports disposed between the frame elements to allow airflow from one side of the cage to the other.

[0049] In an embodiment the acoustic foam includes open cell PU foam. The PU foam is to slow the air flow and dissipate turbulence incident on the leading edge of the body. The PU foam in some embodiments is about 30kg / m3but could be 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50kg / m3.

[0050] In an embodiment the mount is one or more legs on which the cap body stands.

[0051] In an embodiment the mount may be the acoustic foam itself in which the cap body may be held.

[0052] In an embodiment the selected distance above the rim of the acoustic entry port is 1mm.

[0053] In an embodiment the selected distance above the rim of the acoustic entry port is 0.5mm, 0.75mm, 1.22mm, 1.5mm, 1.75mm or 2mm, 2.5mm, 2.2mm, or other suitable distance for facilitating laminarization of the flow.

[0054] In an embodiment the cap has a chord, which is a height between the bottom face and the top face, of 10mm, but it may be useful to have the chord be 5mm, 7.5mm, 12.5mm, 15mm, 17.5mm, 20mm, 22.5mm, 25mm, 27.5mm or 30mm.

[0055] In an embodiment there is a floor at the level of the rim of the acoustic entry port so that, when the cap is mounted on the mount (or spacer) there is provided a channel between the lower wall of the cap body to promote laminarization.

[0056] In accordance with one aspect of the present invention there is provided a cover suitable for an acoustic inlet port of a microphone, the cover including: an aerofoil body including a lower wall and an upper wall, the upper wall separated at a peak by a distance of a selected chord, such that the upper wall extends gradually upwardly from the lower wall to the peak, and extending gradually downwardly to meet the lower wall at one or more peripheral edges, the aerofoil body being configured to deflect an airflow incident on one of the one or more peripheral edges, so that a portion of it passes along the upper and lower surfaces to another peripheral edge; and a mount suitable for mounting the aerofoil body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port.

[0057] In one embodiment the arrangement is such that the cap body is configured to facilitate the laminarization of an airflow streamline incident on one of the one or more peripheral edges along the upper and lower surfaces to another peripheral edge.

[0058] In one embodiment the upper wall includes ramps which are curved or straight, such that the cap body is a hump, or substantially frusto-conical or substantially conical, or substantially pyramidal or substantially frusto-pyramidal.

[0059] In one embodiment the cap body includes radiused edges.

[0060] In one embodiment the mount includes one or more legs disposed at one or more corners of the lower wall.

[0061] In one embodiment there are four legs.

[0062] In one embodiment the legs have rounded portions at least on a leg portion intended to be in a laminarization zone.

[0063] In one embodiment there is provided a microphone unit with an acoustic inlet port and a cover for the acoustic inlet port as hereindescribed.

[0064] In one embodiment the microphone unit includes a cage disposed over the acoustic inlet port, and inside the cage is disposed the cover, the cage further including acoustic foam disposed around the main body of the cover.

[0065] In one embodiment the cage includes peripheral frame elements and ports disposed between the frame elements to allow airflow from one side of the cage to the other.

[0066] In one embodiment the selected distance above the rim of the acoustic entry port is 1mm.

[0067] In one embodiment the selected distance above the rim of the acoustic entry port is 0.5mm, 0.75mm, 1.22mm, 1.5mm, 1.75mm or 2mm, 2.5mm, 2.2mm, or other suitable distance for facilitating laminarization of the flow.

[0068] In one embodiment the cage includes a floor at the level of the rim of the acoustic entry port to provide a laminarisation zone or channel between the lower wall of the cap body to promote laminarization.

[0069] In accordance with one aspect of the present technology there is provided a microphone unit with a cover which includes a body including a lower wall and an upper wall which meet at one or more peripheral edges, the body being for deflecting an airflow streamline incident on one of the one or more peripheral edges along the upper and lower surfaces to another peripheral edge; and a mount for mounting the aerofoil body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port.

[0070] In accordance with one aspect of the present invention there is provided a cover for a microphone, the cover including: a cap configured to mount over an acoustic entry port of a microphone, wherein the cap includes: a main body having a base wall having one or more peripheral edges, the base wall being configured to be disposed at a selected distance above the acoustic entry port, and a top contoured wall which extends from adjacent the one or more peripheral edges of the base wall to an upper portion;the base wall being sized to extend beyond a periphery of the acoustic entry port such that in use, air flowing toward the acoustic entry port is incident on one of the base wall peripheral edges to flow across the base wall towards another of the base wall peripheral edges; and a stand for mounting the main body in a position such that the base wall is spaced from an upper rim of the acoustic entry port to facilitate a slower and laminarised airflow under the base wall from one edge to the other edge.

[0071] In accordance with one aspect of the present technology there is provided a cover for an acoustic inlet port of a microphone, the cover including: a body with a roof wall and a roof wall mount, wherein the roof wall, when installed, is spaced from a rim of the acoustic inlet port of the microphone, such that the roof wall allows air to pass under it from an inlet edge to an outlet edge.

[0072] In an embodiment there is an inlet port at the inlet edge and an outlet port at the outlet edge.

[0073] In an embodiment there is a plurality of inlet ports and a plurality of inlet edges and a plurality of outlet ports and a plurality of outlet edges.

[0074] In accordance with another aspect of the present invention there is provided a microphone with a cover disposed atop a rim of an acoustic inlet port, the cover including: at least one laminarisation zone which includes at least one inlet region and at least one outlet region to facilitate the laminarization of airflow between the at least one inlet region and the at least one outlet region.

[0075] In an embodiment the cover may be multidirectional such that the inlet region and outlet regions are interchangeable such that air may flow in either direction, either from the inlet region to the outlet region or from the outlet region to the inlet region.Brief Description of Drawings

[0076] So that the invention may be more clearly understood, an embodiment of it will hereinafter be described with reference to the drawings and in those drawings:

[0077] Figure l is a perspective view of a wireless microphone with a production cover over the acoustic inlet port in accordance with an embodiment of the invention. The cover is of a domed shape or simple aerofoil; the microphone case is shown with a door open to show an internalarrangement of the microphone assembly and electronics, and with acoustic foam removed for clarity;

[0078] Figure 2 is another perspective view of Figurel, showing the cover from another angle, and again, foam removed for clarity;

[0079] Figure 3 is yet another perspective, showing the microphone clip at the back, and the cover over the acoustic inlet port for a microphone, foam removed for clarity of display;

[0080] Figure 4 is an isometric view of the wireless microphone prototype and cover prototype, being of a pyramidal shape;

[0081] Figure 5 is a plan view of the prototype shown in Figure 4 with foam removed to show the cover more clearly;

[0082] Figure 6 is a perspective view of the prototype shown with acoustic foam in place;

[0083] Figure 7 is a graph showing a frequency sweep of wind noise reduction in which a top line shows a reference condition without a wind cap, and a lower line shows a reduction in wind noise with a cover in accordance with an embodiment of the present invention installed on the reference microphone;

[0084] Figure 8 shows an isometric view of an embodiment of wind cap body shown from above;

[0085] Figure 9 shows an isometric view of the cap body and mounting feet of Figure 8, from underneath; and

[0086] Figure 10 is a side elevation view, part sectioned, of a top portion of the microphone unit showing the cage, chamber, acoustic inlet port, cage floor and domed body.Description of Embodiments

[0087] Referring to the drawings there is shown a microphone unit generally indicated at 10. The microphone unit 10 is of a wireless type, and designed to be clipped to a clothing item or held in the palm of a hand. A clip is shown at 12, and there is also shown transmitting electronics and receiving electronics generally at 14, internal to a microphone housing 15, and a microphone 16 and acoustic entry port 18, with a rim 19 opening onto a cage void 5, in particular onto a cage floor 17.

[0088] The microphone 16 is omnidirectional, has a frequency range response of 20Hz to 20kHz, a signal-noise ratio of about 73dB, and a transmission range of 100m. The sample rate isabout 48kHz. The skilled reader will understand that various kinds of microphone are suitable for use in the microphone unit.

[0089] To reduce wind noise and other extraneous pops and plosives, a cover 20 is provided. The cover 20 is a cap body 22 and a mount 24 for holding the cap body 22 at a selected height above the cage floor 17, the same height as the rim 19 of the acoustic entry port 18, so that a laminarization zone 28 is formed to facilitate laminarization of air which may be flowing from one side 11 to another 13 of the housing 15, along a pathway, say, shown by line 99. Another degree of laminarization is also facilitated by directing a portion of the incoming airflow 99 over the cap body 22, shown by line 98.

[0090] The cap body 22 includes a lower wall 25 and an upper wall 26 which meet at one or more peripheral edges 27, and the mount 24 mounts the cap body 22 on or relative to the cage floor 17 so that the lower wall 25 in use is spaced a selected distance, which is between 0.5mm and 1mm, from the cage floor 17, or spaced from the rim 19 of the acoustic inlet port 18 so that a low channel or passageway or pathway 99 is formed between the cage floor 17 and the lower wall 25.

[0091] The upper wall 26 may include four ramps as shown in Figures 4 and 5. End ramps 65 extend from the lower wall 25 up to a peak 67. Front and rear ramps 66 extend from the lower wall edge to the peak 67. The peak 67 in Figure 4 and 5 is elongate, providing a prismoid pyramidal shape.

[0092] A similar shape is shown in Figures 8 and 9, and 1, 2 and 3, but the prismoid pyramidal shape has more curved or radiused surfaces, and radiused or rounded peak and edges for smoother airflow incident from different angles.

[0093] The distance between the upper and lower surfaces is the chord 85 shown in Figure 9. The length of the chord may be from lower wall 25 or 125 to peak 85, and may be as hereindescribed.

[0094] The lower wall 89 is 5.6mm wide.

[0095] In plan view, the lower walls are equal in length so the base is square.

[0096] The chord 85 is 2.85mm high, meaning the cap is 2.85mm high.

[0097] The port width 88 is 2.45mm.

[0098] The port depth 87 is 2.25mm.

[0099] The channel or laminarization zone height 86 is 0.75mm.

[0100] The mount 24 may be a stand, and in the embodiment shown the stand is in the form of legs 51, 52, 53, and 54 disposed in the corners of the lower wall 25. The legs extend through holes in the cage floor 17 and mount on a structure, which may be the microphone chassis, adjacent the underside of the cage floor 17. The legs 51, 52, 53 and 54 are elongate cylinders, rounded in section to improve laminarization from each direction, through the passageway or pathway 99 and like ones at any angle thereto.

[0101] The passage of the air in the pathways 98 and 99 can be made more efficient and more laminar by the use of a cap body 22 with an aerofoil, even a NACA profile, and the cap body 22 may be unidirectional, or symmetrical, for that purpose. The microphone and cap is designed to laminarise flows along pathway 99 and from any angle parallel to that cage floor plane 17, and indeed any other angle.

[0102] The signal of interest may come from any angle, and indeed the wind may come from any angle as well. The wind may be from a speaker or singer or other signal of interest, while the wind may also come from a different source from a different direction. That means that a user may be holding the microphone so that the wind would flow, say, over the side 11, first, and then flow out the cage chamber 5 on side 13. So, the NACA profile may be like an aeroplane wing section, known from the art. The cap body 22 may be bidirectional or multidirectional, or may be a flat plate, a dome, a cone, a pyramid, a frusto conical or frusto pyramidal arrangement, depending on the efficiency required, and the level of directionality desired. There may be radii on each edge to smooth the flow over the top surface of the cap body 22.

[0103] The cap body 22 may be additively formed, or moulded, or cast, or machined, from metal or plastic, and may be solid or hollow. Most usefully the upper 26 and lower 25 walls are smooth to facilitate attachment or laminarization of air flowing over them, rather than turbulent flow.

[0104] The cover 20 or cage 5 also includes acoustic foam 30 disposed around the periphery of the main body 22. The acoustic foam 30 may form the stand 124 in which the cap body 22 may be embedded, perhaps with reinforcing rods or filaments extending to cage 5 elements for structural reinforcement.

[0105] The cage 5 may be filled with acoustic foam 30. The cage also includes open ports 6, 7, 8, 9 on each side so that air may flow not only in one direction as shown by 99, but from any side, and the cover 20 may direct airflow into and out of the cage ports, and the laminarization of that flow, and also the slowing of that flow through the cage 5, is believed to reduce the popsand plosives and clipping of the signal resulting. The slower airflow also facilitates dissipation of turbulence in the flow.

[0106] The ports 6, 7, 8, 9 may include acoustic mesh covering - between about 150 to 500 Rayls. The mesh may be in a range of approximately, and selected from the quantities 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650 or 700 Rayls. The mesh covering partially blocks wind but whose acoustic impedance can be chosen to control the acoustic behaviour. Stainless steel wire mesh or high-quality metal alloys like Inconel, Monel, or Nickelbased alloys may be used or others known to the person of skill, offering durability and acoustic control. Weaves such as Dutch, Reverse Dutch, or Twilled weaves provide the right balance of airflow resistance and sound attenuation.

[0107] The acoustic foam 30 includes open cell PU foam. The PU foam is to slow the air flow incident on the leading edge of, and then through, the cage void 5 so that laminarization is performed in an improved manner.

[0108] Figure 7 shows a reduction in wind noise when the wind cap body 22 is mounted on a microphone shown in Figure 1. At lower frequencies, which are up to about 300Hz, which are the frequency band more disrupted by wind and plosives, it can be seen that the improvement is around -lOdB while at higher frequencies the improvement is slightly less in some bands.

[0109] Figures 8 and 9 show another embodiment of wind cap body 122 and stand legs, the body having rounded edges to improve laminarization.Parts list

[0110] Cage void 5

[0111] Cage inlet ports 6, 7, 8, 9

[0112] Microphone unit 10

[0113] Microphone Housing side 11

[0114] Microphone Housing other side 13

[0115] Clip 12

[0116] Electronics and processor 14

[0117] Microphone housing 15

[0118] microphone 16

[0119] Acoustic entry port 18

[0120] Rim 19

[0121] Cage floor 17

[0122] Cover 20

[0123] Cap body 22, 122

[0124] Cap lower wall 25

[0125] Cap upper wall 26

[0126] Mount 24, 124

[0127] Acoustic foam 30

[0128] Mount legs 51, 52, 53, 54

[0129] Ramped upper walls 65, 66, 165, 166

[0130] Peak 67

[0131] Laminarization zone 28

[0132] Chord 85

[0133] Airflow path 98

[0134] Airflow path 99

[0135] It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.

[0136] It is to be understood that any prior art publication referred to herein does not constitute an admission that the publication forms part of the common general knowledge in the art.

[0137] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

CLAIMS:

1. A cover suitable for an acoustic inlet port of a microphone, the cover including: an aerofoil body including a lower wall and an upper wall, the upper wall separated at a peak by a distance of a selected chord, such that the upper wall extends gradually upwardly from the lower wall to the peak, and extending gradually downwardly to meet the lower wall at one or more peripheral edges, the aerofoil body being configured to deflect an airflow incident on one of the one or more peripheral edges, so that a portion of it passes along the upper and lower surfaces to another peripheral edge; and a mount suitable for mounting the aerofoil body so that the lower wall in use is spaced a selected distance from a rim of the acoustic inlet port.

2. The cover in accordance with claim 1 wherein the arrangement is such that the cap body is configured to facilitate the laminarization of an airflow streamline incident on one of the one or more peripheral edges along the upper and lower surfaces to another peripheral edge3. The cover in accordance with claim 1 or 2 wherein the cap body is an aerofoil.

4. The cover in accordance with claim 1 or 2 wherein the upper wall includes ramps which are curved or straight, such that the cap body is a hump, or substantially frusto-conical or substantially conical, or substantially pyramidal or substantially frusto-pyramidal.

5. The cover in accordance with claim 1 or 2 or 3 or 4 wherein the cap body or is unidirectional or multidirectional.

6. The cover in accordance with any one of claims 1 to 5 wherein the upper and lower walls are smooth to facilitate attachment or laminarization of air flowing over them, rather than turbulent flow.

7. The cover in accordance with any one of claims 1 to 6 wherein the cap body is a metal or a plastic.

8. The cover in accordance with any one of claims 1 to 7 wherein the cap body is ABS, PE, HDPE, or other like polymers, or aluminium, steel, titanium, or other alloys of metals.

9. The cover in accordance with any one of claims 1 to 8 wherein the cap body is additively formed such as by 3D printing.

10. The cover in accordance with any one of claims 1 to 9 wherein the cap body is extruded or moulded or cast, or machined from a block.

11. The cover in accordance with any one of claims 1 to 10 wherein the cap body includes radiused edges.

12. The cover in accordance with any one of claims 1 to 11 wherein the mount includes one or more legs disposed at one or more corners of the lower wall.

13. The cover in accordance with any one of claims 1 to 12 wherein there are four legs.

14. The cover in accordance with any one of claims 1 to 13 wherein the legs have rounded portions at least on a leg portion intended to be in a laminarization zone.

15. A microphone unit with an acoustic inlet port and a cover for the acoustic inlet port in accordance with any one of claims 1 to 14.

16. The microphone unit in accordance with claim 15 including a cage disposed over the acoustic inlet port, and inside the cage is disposed the cover, the cage further including acoustic foam disposed around the main body of the cover.

17. The microphone unit in accordance with any one of claims 15 to 16 wherein the cage includes peripheral frame elements and ports disposed between the frame elements to allow airflow from one side of the cage to the other.

18. The microphone unit in accordance with any one of claims 15 to 17 wherein the mount may be the acoustic foam itself in which the cap body may be held.

19. The microphone unit in accordance with any one of claims 15 to 18 wherein the selected distance above the rim of the acoustic entry port is 1mm.

20. The microphone unit in accordance with any one of claims 15 to 19 wherein the selected distance above the rim of the acoustic entry port is 0.5mm, 0.75mm, 1.22mm, 1.5mm, 1.75mm or 2mm, 2.5mm, 2.2mm, or other suitable distance for facilitating laminarization of the flow.

21. The microphone unit in accordance with any one of claims 15 to 20 wherein the cover or cage includes a floor at the level of the rim of the acoustic entry port to provide a channel between the lower wall of the cap body to promote laminarization.

22. A cover for a microphone, the cover including: a cap configured to mount over an acoustic entry port of a microphone, wherein the cap includes: a main body having a base wall having one or more peripheral edges, the base wall beingconfigured to be disposed at a selected distance above the acoustic entry port, and a top contoured wall which extends from adjacent the one or more peripheral edges of the base wall to an upper portion; the base wall being sized to extend beyond a periphery of the acoustic entry port such that in use, air flowing toward the acoustic entry port is incident on one of the base wall peripheral edges to flow across the base wall towards another of the base wall peripheral edges; and a stand for mounting the main body in a position such that the base wall is spaced from an upper rim of the acoustic entry port to facilitate a slow airflow under the base wall from one edge to the other edge.

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