Microphone cover apparatus and method

Abstract

A microphone cover apparatus includes a tubular body, and a liner within the tubular body. A method of recording sound includes disposing a microphone in a microphone cover apparatus, the microphone cover apparatus comprising a tubular body, a liner within the tubular body, and a ridge projecting radially inward from an interior surface of the liner; and angling the tubular body such that its axis is substantially directed towards a sound source.

Description

Microphone Cover Apparatus and MethodBenefit of Earlier Applications[%3] This application claims priority from U.S. provisional application 63 / 612,199, filed December 19, 2023.Technical Field[%3] The present invention relates to microphones in general, and microphone cover apparatus and methods in particular.Background[%3] Sound intended to be detected by a microphone, and the microphone itself, can be changed and / or distorted by various aspects of the environment, e.g., wind, rain, snow, heat, light, and near field acoustic reflection, to name a few. Other affects, such as clumsy handling of the microphone, or noise from the environment, can also distort the sound intended to be detected by the microphone, e.g., by constructive or destructive interference. Microphone covers may be used to mitigate against such change, interference, and distortion.[%3] Using wind as an example, with reference to Fig. 15, microphones may be inserted into what is known in the art as a blimp 908, being a wind-attenuating cover typically having an elongate cylindrical shape with spherical ends and means to insert and remove the microphone. Another wind-attenuating cover known in the art is a dead cat (e.g., dead cat 909), which is made of a sound-absorbing fuzzy fabric and / or fur, and is typically shaped like a sock that is sized to enclose the blimp (and microphone therein) with an opening on one end for insertion and removal of the blimp. The dead cat is typically disposed on, i.e., outside of, the blimp.[%3] There is a demand for further and alternative means to prevent distortion of sound intended to be detected by microphones.Summary of Invention[%3] In accordance with a broad aspect of the present invention, there is provided a microphone cover apparatus, comprising: a tubular body, and a liner within the tubular body.[%3] In accordance with another broad aspect of the present invention, there is provided a method of recording sound, the method comprising: disposing a microphone in a microphone cover apparatus, the microphone cover apparatus comprising a tubular body, a liner within the tubular body, and a ridge projecting radially inward from an interior surface of the liner; and angling the tubular body such that its axis is substantially directed towards a sound source.[%3] It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all within the present invention. Furthermore, the various embodiments described may be combined, mutatis mutandis, with other embodiments described herein. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.Brief Description of the Drawings[%3] Referring to the drawings wherein like reference numerals indicate similar parts throughout several views, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:(%4) Fig. 1 is an end perspective view of a microphone cover apparatus, according to one embodiment;(%4) Fig. 2 is a table, depicting four illustrative embodiments of a microphone cover apparatus of the present invention, with the corresponding results of fluid dynamics modelling tests, which visualize the laminar flow of each embodiment, when exposed to wind with a speed of 0.001 m / s, 0.01 m / s, 0.1 m / s and 1 m / s;(%4) Fig. 3 is a table, depicting the four embodiments of Fig. 2, and corresponding results of laminar flow modelling tests at various speeds (0.001 m / s, 0.01 m / s, 0.1 m / s and 1 m / s), wherein the laminar flow images are generated with a cube shaped object 300 placed between the wind source and each embodiment;(%4) Fig. 4 is a top perspective view of a microphone cover apparatus, according to one embodiment, including an example microphone that may be used with the microphone cover apparatus, and of a dead cat-type microphone cover, which may be included in the microphone cover apparatus;(%4) Fig. 5 is a top perspective view of a microphone cover apparatus, according to one embodiment;(%4) Fig. 6 is a partly cut away top perspective view of an end of the embodiment of Fig. 5;(%4) Fig. 7 is top perspective view of a microphone cover apparatus, according to one embodiment, wherein the embodiment of Fig. 5 further includes a pre-shell layer, which in the illustrated embodiment is a neoprene layer;(%4) Fig. 8 is an end perspective view of the embodiment of Fig. 7;(%4) Fig. 9 is a partly cut away end perspective view of the embodiment of Fig. 7, with foam plugs 902, which may be inserted into an end of the embodiment of Fig. 7;(%4) Fig. 10 is an end perspective view of a microphone cover apparatus, according to the embodiment of Fig. 9, with the foam plug inserted;(%4) Fig. 11 is a top perspective view of a partly disassembled microphone cover apparatus, according to one embodiment, including an outer shell comprising a first end segment, a middle segment, and a second end segment, for enclosing the other components of the microphone cover apparatus illustrated beneath the outer shell;(%4) Fig. 12 is a partly cut away side perspective view of the first end segment of the outer shell, and an end of the other components of the microphone cover apparatus, with a cut-away section 12a of the neoprene layer showing placement of the foam plug;(%4) Fig. 13 is a partly cut away side perspective view of the second end segment of the outer shell layer, with a partly cut away section of the other components of the microphone cover apparatus to be inserted into the second end segment, with a microphone cord running into the second end segment and out an exit hole;(%4) Fig. 14 is a side perspective view of a microphone cover apparatus, according to the embodiment of Fig. 7, in an assembled configuration, including optional cable coupling brackets 166 on the outer shell;(%4) Fig. 15 is a top perspective view of microphone cover apparatus of the prior art, including dead cat 909, and blimp 908;(%4) Fig. 16 is an illustration of several components of a microphone cover apparatus, according to various embodiments;(%4) Fig. 17 is a graph, comparing the decibel (dB) suppression test results of blimp 908 of the prior art, and a microphone cover apparatus, according to one embodiment of the present invention;(%4) Fig. 18 is a graph of measurements obtained during testing, with decibel measurements (dB) on the vertical axis and sound frequency measurements (Hz) on the horizontal axis, wherein line 18a is the baseline decibel level, and line 18b is decibel level suppressed by blimp 908, as measured in dry and low or no wind conditions;(%4) Fig. 19 is a graph of measurements obtained during testing, with decibel (dB) measurements on the vertical axis and sound frequency measurements (Hz) on the horizontal axis, wherein line 19a is the baseline decibel level, and line 19b is decibel level suppressed by the embodiment of Fig. 14, measured in dry and low or no wind conditions;(%4) Fig. 20 is a graph of measurements obtained during testing, showing noise suppression measurements for prior art blimp 908 and dead cat 909 as compared to several illustrative embodiments of the present invention;(%4) Fig. 21 is a graph of measurements obtained during testing, showing noise suppression measurements for prior art blimp 908 and dead cat 909 as compared to several illustrative embodiments of the present invention;(%4) Fig. 22 is a top perspective view of a ridge according to one embodiment of a microphone cover apparatus;(%4) Fig. 23 is another top perspective view of the ridge of Fig. 22;(%4) Fig. 24 is a top perspective view of a liner of a microphone cover apparatus, according to one embodiment;(%4) Fig. 25 is a diagram illustrating a set up for experimental testing, the results of which are set out in Table 1; and(%4) Fig. 26 is a graph displaying the measurements of an active noise cancellation test of the present invention, comparing wind speed in km / h on the vertical axis and active noise cancellation in decibels (dBA) on the horizontal axis.Detailed Description of Embodiments[%3] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.[%3] A microphone cover apparatus is provided. Fig. 1 depicts one embodiment of a microphone cover apparatus 100, comprising a tubular body 110 with a liner 120 within the tubular body. The body and the liner may be integral.[%3] A microphone may be placed within the tubular body. Placing the microphone within the tubular body may provide directionality to the microphone. In other words, this configuration may block sound waves from reaching the microphone, e.g., sound waves coming from a source perpendicular to the long axis of the tubular body, and in particular sound waves of frequencies above 1,100 Hz, e.g., above 1,200 Hz. The tubular body may reduce the amount of ambient noise detected by the microphone when in use. The tubular body also limits the effect of wind on the microphone by acting as a wind shield or wind screen.[%3] The tubular body, with the microphone therein, may be pointed in a direction of a sound desired to be detected. The microphone may be placed into the tubular body, and the tubular body may have an end pointed in the direction of the sound desired to be detected. During testing, it was observed that sound detected by this configuration exhibited a "hollow" characteristic due to an echo effect, i.e., reflection of sound within the tubular body—this issue is addressed, e.g., by the introduction of one or more ridges (among other optional structures), discussed further below. A mesh may be disposed at the opening of the tubular body to reduce headwind turbulences. A second liner may be disposed within the tubular body to reduce turbulence and partially transform the turbulent air flow into laminar air flow. The second liner may be elongate and cylindrical, sized and shaped to line the interior of the tubular body. Put differently, the second liner may line the inside of the first liner. The second liner may be made of any number of materials, e.g., fabric and / or foam. The second liner may be flexible or it may be rigid, depending on the environment and context in which it is to be used. For example, the second liner may be made of an acoustic fabric, which may reduce ambient and near-field acoustic reflection. A soft fabric of various materials may be selected to reduce the amplitude of higher frequencies. A specific acoustic fabric may be selected to dampen certain undesired frequencies. The liner and the second liner may advantageously reduce the echo effect. Material of the tubular body, the liner and / or the second liner may be selected to reduce resonances. Various aspects of the liner, e.g., shape, texture, and material, may be selected to reduce resonances within the tubular body. Various aspects of the second liner, e.g., shape, texture, and material, may be selected to reduce resonances within the tubular body and liner. The microphone cover may reduce constructive interference and destructive interference.[%3] The liner 120 may include a ridge 122. Ridge 122 may project radially inward from an interior surface 112 of the tubular body. Fig. 1 depicts one embodiment where ridge 122 has a domed shape. The ridge may extend out from the inner surface of the tubular body, and the ridge may arc around, and extend back to the inner surface of the tubular body. The ridge may have an open cavity 124. The ridge may spiral along an internal surface of the tubular body.[%3] The ridge may have any number of orientations. Such orientations may be selected to change air boundary layers formed within the tubular body. With reference to Fig. 2, three different embodiments are shown, compared to a tubular body without ridges 122d. These include an embodiment in which the ridge may have a helical orientation 122a, wherein the ridge 122i extends helically about a long axis of the body. The ridges may be concentric with a long axis of the liner. The long axis of the body may be concentric with a long axis of the liner. There may be a plurality of ridges 122i aligned with one another, arranged side-by-side, each extending helically about the long axis of the liner. There may be enough ridges to substantially cover the inner surface of the body. There may be a gap between each ridge and the next. The ridges may spiral around next to one another. The pattern of the ridges may be repeated along the inner surface of the tubular body.[%3] One or more of the ridges may be hollow. In other words, there may be a space 124 (as illustrated in Fig. 1) defined between the ridge of the liner and the tubular body. For example, in an embodiment where the ridge has a helical orientation, a helical length of the ridge may be hollow. This variation of the helical orientation may be referred to as a "twisted open" orientation 122b. In such an embodiment, in cross section, each ridge 122ii may have a domed shape.[%3] Figs. 22-24 illustrate ridge 122ii, present in the "twisted open" embodiment 122b. The tubular body 110 may have an axial length of about 300 mm (e.g., 250-350 mm), and the ridge may have an approximately 540° arc from one end of the axial length of the tube to the other. Figs. 22-24 illustrate a liner having ridges with an arc of approximately 270° for a body (omitted to facilitate illustration of the ridges) having an axial length of approximately 150 mm. Such ridges may be coupled together and / or may be coupled to the body, thereby forming an axial length of approximately 300 mm (e.g., 280 mm - 320 mm) and an arc of approximately 540° (e.g., 520°-560°).[%3] In another embodiment, the ridge may have a perpendicular orientation 122c, wherein the ridge extends perpendicular to the long axis of the tubular body. The ridge may extend a full 360°, forming an annular structure protruding into the interior of the liner. Alternatively, the ridge 122iii may have a tooth orientation, wherein the ridge extends less than 360°, e.g., 20°, forming a tooth structure protruding into the interior of the liner. In one embodiment, there may be a plurality of ridges. For example, multiple ridges may be spaced apart from one another and arranged in columns (i.e., axially) and rows (i.e., radially) on the interior of the liner. The columns may be staggered such that space between teeth in one row is axially aligned with a tooth of a subsequent row. This ridge orientation may be referred to as the "staggered teeth" orientation.[%3] The tubular body 410 may be sized to receive an elongate microphone 402 therein. The microphone cover may include one or more layers relative to the position of the microphone. For example, the microphone cover may include one or more of: a dead cat layer (e.g., dead cat layer 909 illustrated in Fig. 4), a foam layer, a rubber layer, a neoprene layer, a waterproof layer, etc. Neoprene or rubber may be advantageous as they may reduce ambient noise, near field acoustic reflections and bouncing, and side directional noise from reaching the microphone. Such materials also prevent water or other fluids from penetrating through such layers into internal layers and components, such as the microphone, protecting them from damage and avoiding any distortion such fluid may cause to the detected sound, e.g., if the microphone is to be used in inclement weather.[%3] For example, a dead cat layer, a foam layer (which may be referred to as a wind shield), or both, may be disposed between the microphone and the liner. A second dead cat layer and / or foam layer may be disposed exterior to the tubular body. Fig. 5 illustrates a dead cat layer 909 with a microphone therein. The dead cat layer 909 is disposed within the liner of the tubular body 410. The dead cat and / or foam layers may reduce the velocity of wind at the microphone, reducing or filtering air vortices and reducing noise caused thereby. Fig. 6 provides another perspective of the microphone cover apparatus with the dead cat layer within the liner of the tubular body.[%3] Further, a pre-shell layer, which in the illustrated embodiment is a neoprene layer 406, may be disposed around the tubular body's exterior, as shown in Fig. 7 and Fig. 8. In these embodiments, the neoprene layer 406 may have a length greater than an axial length of the tubular body 410, such that when the tubular body is disposed within the neoprene layer, an end of the neoprene layer extends beyond an end of the tubular body, thereby defining a recessed area 802. Additional noise-attenuating material, such as foam, may be provided or inserted into such ends such that the ends are flush. Such a foam plug 902 is depicted in Fig. 9. As shown in Figs. 9 and 10, the foam plug may be inserted into in the recessed area defined by the end of the neoprene layer that extends axially beyond the tubular body. In this aspect, the foam may act as a plug on an end of the microphone cover. Various densities of foam may be used for the plug, which may be selected according to a particular application, e.g., based on environmental factors and / or the frequencies of sound desired to be reduced. The density may correspond to the porosity of the foam plug.[%3] The foam plug may include one or more foam discs, for example, three foam discs. There may be a gap between the foam discs. In embodiments with multiple foam discs, each disc may have different densities. For example, the outer disc may have a density that is lesser than that of the middle disc, and the middle disc may have the same or a different density than the inner disc.[%3] In testing, a preferred embodiment 904 of a microphone cover including a foam plug had an outer disc, a middle disc, and an inner disc. The outer disc had a first density, the middle disc had a second density, and the inner plug also had the second density. The first density was approximately half that of the second density. With reference to Figs. 20 and 21, during testing it was observed that this embodiment performed best when compared with other tested embodiments.[%3] As shown in Figs. 11-14, the microphone cover may further include an outer shell 150 to act as a housing. The shell may be made of a hard material. The shell may be integral or may have multiple segments, e.g., as illustrated in Fig. 11, it may have a first segment 151, a second segment 152, and a third segment 153. The segments may be arranged end-to-end and have the same inner diameter and / or outer diameter. The outer shell's inner diameter may be large enough to accommodate a neoprene or other similar layers, as shown in Fig. 11. The other components of the apparatus may fit tightly within the outer shell. The neoprene layer, if present, may fit tightly within the outer shell. Alternatively, the tubular body may fit tightly within the outer shell.[%3] An end cap may be placed on either or both ends of the tubular body. The end cap may be placed exterior to the one or more plugs, if present. The end cap may be made of a hard material. The end cap may be integral with the outer shell. The end cap may include holes, and as such may be referred to as a grill, to permit sound waves to pass through the end cap while limiting the effect of wind on the microphone within the tubular body.[%3] As can be seen in Figs. 11 and 13, the shell may include an exit hole 160 for a cable 161 of the microphone. The other layers of the microphone cover may include corresponding exit holes. The shell may act as a shield to reduce air velocity and thereby reduce the effect of wind on the microphone. The shell may be lined with an acoustic fabric. The shell may be made of a material with a high reflection coefficient, such that if the microphone were placed directly therein without any other layers described herein, the material of the shell may cause sound to be reflected inside the shell, resulting in resonance and reverberation. This would affect acoustic reflection, transmission, and absorption coefficients. The microphone cover also protects the microphone against impact.[%3] The shell may include a drainage hole 162 to permit drainage of rain or other fluid that may enter the apparatus. One embodiment of drainage hole 162 can be seen in Fig. 11 and 12. Other layers, including for example the body and liner, may have corresponding drainage holes. The drainage holes may be aligned with one another.[%3] In one embodiment, the liner may have a drainage channel 130 extending parallel to the long axis of the liner, through the one or more ridges, extending radially from the body at least partway into the liner. Drainage channel 130 may extend along the internal surface of the tubular body, e.g., as a cut out portion of the liner. As illustrated in Fig. 1, the drainage channel may extend through the ridges in the axial direction of the tubular body and may extend from the internal surface of the tubular body radially inward partway through the ridges.[%3] The shell may include one or more brackets 166, which may be couplable to the cable 161. In use, these brackets may prevent shock, i.e., the brackets may prevent force on the cable from being transferred to the microphone.[%3] A method for assembling a microphone cover may include inserting a microphone into tubular body with a liner. Alternatively, the microphone may be inserted into an inner layer, which may include foam and / or a dead cat, and then the inner layer and the microphone therein may be inserted into the liner of the tubular body. The tubular body may be inserted into a pre-shell layer, which may include neoprene (further, or in the alternative, the outer layer may include rubber or similar materials that preferably have acoustic absorption and shock-absorbing qualities). For example, the tubular body may be rolled within a sheet of neoprene, such that the neoprene forms a cylindrical shape around the tubular body. Foam may be used to plug the recess (if any) extending from an end of the tubular body to an end of the pre-shell layer. The pre-shell layer may be inserted into an outer shell. Alternatively, the tubular body may be inserted into the outer shell, e.g., in embodiments without a pre-shell layer.[%3] The microphone cover may be coupled to a microphone used in active noise reduction apparatus and methods and / or sound wave generation apparatus and methods. For example, the instant microphone cover may be coupled to one or more of the microphones described in the following properties owned by Zerosound Systems Inc. of Calgary, Alberta, Canada: CA 3,138,951; CA 3,138,954; US 11,151,975 B2; US 10,665,219 B2; and other apparatus and methods sold by Zerosound Systems Inc. For example, microphones of such apparatus and methods may be inserted into the microphone cover described herein. Accordingly, a microphone cover for use in active noise cancellation apparatus and methods is provided.[%3] The microphone cover may advantageously protect the microphone from the environment. For example, the microphone cover may act as a barrier preventing water from damaging the microphone. The microphone cover may reduce problems related to precipitation, ambient noise, traffic, and wind, among others. For example, wind turbulence may be reduced by the ridges of the liner within the tubular body. The microphone cover may extend the useful lifespan of microphones, especially microphones used outdoors for extended periods of time.[%3] In testing, it was observed that a tubular body alone (i.e., without a liner) affected sound detected by the microphone disposed within the tubular body. In particular, it was observed that the sound had a "hollow" characteristic. This characteristic was advantageously reduced when disposing the liner between the tubular body and the microphone.[%3] The microphone cover, according to one embodiment, was tested in the context of noise cancellation, as follows. A first set of tests was conducted on a first grassy field near a highway during conditions of wind and rain. A second set of tests were conducted on a grassy field that is a polo field in relatively quiet and dry conditions. For each test, an embodiment of the instant microphone cover was compared with a blimp of the prior art to act as a control.[%3] It is to be appreciated that the microphone cover may be used to provide directionality to microphones used in a variety of applications. For example, directional microphones may be used in active noise reduction apparatus and methods (e.g., US 10,665,219 B2). Embodiments of the instant microphone cover were tested for use with active noise reduction apparatus and methods. With reference to Fig. 25, a speaker 502 was disposed 1-30 m (e.g., 26 m) in a first direction from a first microphone 504. A noise reduction panel 506 (e.g., US 10,665,219 B2) was disposed a further 0.8 m to 6 m (e.g., 1.5 m) in the first direction from the first microphone. A second microphone 508 was disposed a further 2 m to 20 m (e.g., 5 m) in the first direction from the panel. The speaker was configured to emit various types of sound, including white noise, hydraulic fracturing (fracking) noise, and transformer noise. The microphone 504 detected the sound emitted by speaker 502, the panel 506 emitted inverted sound waves actively to reduce the perception thereof by the second microphone 508. The microphone 504 was equipped with a blimp of the prior art, and then with the instant microphone cover.[%3] Table 1, below, together with Fig. 17, illustrate results of testing:Table 1White Noise – Overall dB suppressionTransformer Noise – Overall dBFracking Noise – Overall dBPrior Art BlimpMicrophone CoverPrior Art BlimpMicrophone CoverPrior Art BlimpMicrophone Cover2.38.78.98.58.55.56.86.61.57.97.38.17.56.207.93.99.29.99.55.96.85.110.16.88.37.88.77.68.91.18.66.54.38.48.96.18.17.46.49.17.76.79.14.97.47.29.59.28.98.05.48.57.38.18.87.54.26.35.9AverageAverageAverageAverageAverageAverage6.58.35.96.87.28.1Standard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard Deviation2.81.12.91.61.71.5Max-MinMax-MinMax-MinMax-MinMax-MinMax-Min8.83.38.94.55.24.6 [%3] In testing, the instant microphone cover showed improved noise reduction when compared to a blimp of the prior art.[%3] Even during rainy and windy conditions (winds of approximately 15 km / h and gusts of approximately 25 km / h), the instant microphone cover kept the microphone therein dry. The control device (i.e., the blimp) would have certainly become wet and therefore to preserve the integrity of the of the other tests, a plastic bag was placed on the blimp. Three different noises (emitted by the speaker) were tested, including white noise, transformer noise, and hydraulic fracturing noise, each of which was tested for ten calibrations.[%3] In the second set of tests performed in dry and low- to no-wind conditions, results of the blimp of the prior art (Fig. 18) and the instant microphone cover (Fig. 19) are illustrated. The noise suppression achieved, as detected approximately 50 meters behind the panel 506, using blimps was approximately 3.6 dB, while the noise suppression achieved using the instant microphone cover was approximately 3.9 dB. The noise used for both tests was white noise with frequencies between 50 and 2,000 Hz.[%3] Various liner orientations were also modelled specifically for the reduction of wind turbulence by modelling the various orientations disposed proximate a wind source, the wind source delivering wind in the axial direction of the tubes. The results of such fluid dynamic modelling tests are shown in Figs. 2 and 3. For each orientation, wind velocities of 0.001, 0.01, 0.1, and 1 m / s were modelled. In Figs. 2 and 3, four embodiments were modelled: from left to right, first tube 122d, being a tube without a liner; second tube and liner 122c having a tooth orientation; third tube and liner 122a having a helical orientation; and fourth tube and liner 122b having a twisted open orientation.[%3] Fig. 2 shows a model of laminar flow. With reference to Fig. 3, a cube 300 is disposed between a wind source and the tube to test how the embodiments would behave in the presence of wind vortices, specifically horseshoe vortices. As velocity increases, a horseshoe vortex builds up around and at the back of the cube (i.e., the end of the cube closer to the tube), affecting the velocity of wind entering the tubes. In Figs. 2 and 3, wind speeds are represented as a spectrum of red-orange-yellow-green-blue-indigo-violet, with red representing the fastest wind speed, i.e., the inlet speed indicated in the leftmost column, and violet representing the slowest wind speed, i.e., substantially 0 m / s. In Figs. 2 and 3, structural elements are illustrated in black and structural elements in cross section are illustrated in white. The inlet (not shown) is substantially to the right of each illustrated embodiment, pointed substantially at each embodiment's centre and aligned with its long axis.[%3] In models with (i.e., Fig. 3) and without the cube (i.e., Fig. 2), all four embodiments behave similarly and there is not much difference between them when using a flow rate of 0.001 m / s. It was observed that when the velocity increases to 0.1-1 m / s, the flow inside the third column's tube and liner 122a, having a helical orientation, wind velocity is reduced more than that inside other tested embodiments, suggesting that this orientation is relatively more effective at reducing wind noise. It was observed that the twisted open embodiment 122b provided a more uniform velocity drop inside the liner and at the outlet, indicating that such an orientation may be more effective when wind velocity is dropped to certain levels. In other words, the helical orientation reduces wind velocity by a greater amount overall, while the twisted open orientation reduces turbulence more uniformly / evenly throughout the liner.[%3] With reference to Figs. 20 and 21, embodiments of the instant microphone were compared against various types of noise-attenuating apparatus. The charts in these figures show the reduction of volume (dB) of certain frequencies (Hz) by various embodiments of wind attenuating apparatus. Fig. 20 also shows that high wind increases amplitude of low frequencies significantly for some apparatus, including blimps, while tested embodiments of the instant microphone cover were shown to experience little effect from wind in the recorded spectrum.[%3] Specifically, seven apparatus were tested. A first embodiment 901 included two foam layers and one dead cat layer, a second embodiment 902 included one foam layer and two dead cat layers, a third embodiment 903 included a liner with a helical orientation, a fourth embodiment 904 included three layers of foam, and a fifth embodiment 906 included three layers of foam (with the outer layer having a first density and the other two layers having a second density being approximately 50% more dense than the first density). A sixth apparatus 908 comprising a blimp was used as a control and baseline for the comparison. A seventh apparatus 909 comprising a dead cat was used as a second control, with the expectation it would perform the worst of all tested apparatus.[%3] With reference to Fig. 20, the control apparatus 909 experienced the most noise when the wind speed is high, whereas the blimps remain quiet at low frequencies, mainly below 80 Hz. The embodiments of the present invention, i.e., embodiments 901, 902, 903, 904, and 906, show similar wave forms as control apparatus 908 and 909, but are less affected by wind. As shown in Fig. 20, embodiment 902 provided a superior response compared to the other embodiments and control apparatus.[%3] With reference to Fig. 26, the instant microphone cover was tested for use in an active noise reduction apparatus for various wind speeds. A total of 250 tests were performed on 30-minute intervals. It was observed that the speed of wind had little effect on the effectiveness of the microphone cover. Accordingly, it is believed that the microphone cover will work for any wind speed.Clauses[%3] Clause 1. A microphone cover apparatus, comprising: a tubular body, and a liner within the tubular body.[%3] Clause 2. The apparatus of any one or more of clauses 1-18, further comprising: a ridge projecting radially inward from an interior surface of the liner.[%3] Clause 3. The apparatus of any one or more of clauses 1-18, wherein: the ridge extends helically about a long axis of the body.[%3] Clause 4. The apparatus of any one or more of clauses 1-18, wherein: the ridge is hollow.[%3] Clause 5. The apparatus of any one or more of clauses 1-18, wherein: a helical length of the ridge is hollow.[%3] Clause 6. The apparatus of any one or more of clauses 1-18, wherein: the ridge extends perpendicular to a long axis of the body.[%3] Clause 7. The apparatus of any one or more of clauses 1-18, wherein: the ridge extends the entire inner circumference of the body.[%3] Clause 8. The apparatus of any one or more of clauses 1-18, wherein: a second ridge is axially aligned with the ridge.[%3] Clause 9. The apparatus of any one or more of clauses 1-18, wherein: a second ridge is radially aligned with the ridge.[%3] Clause 10. The apparatus of any one or more of clauses 1-18, further comprising: a pre-shell layer around the tubular body.[%3] Clause 11. The apparatus of any one or more of clauses 1-18, wherein the pre-shell layer is a neoprene layer.[%3] Clause 12. The apparatus of any one or more of clauses 1-18, wherein: the pre-shell layer is axially longer than the tubular body, forming a recess at an end of the pre-shell layer; and a foam plug is disposed in the recess.[%3] Clause 13. The apparatus of any one or more of clauses 1-18, further comprising: an outer shell, comprising a hard tubular casing sized to enclose the tubular body therein; and an opening in the hard tubular casing, to allow sound to travel into the hard tubular casing's interior.[%3] Clause 14. The apparatus of any one or more of clauses 1-18, wherein: the outer shell further comprises a drainage hole, and a microphone wire hole.[%3] Clause 15. A method of recording sound, the method comprising: disposing a microphone in a microphone cover apparatus, the microphone cover apparatus comprising a tubular body, a liner within the tubular body, and a ridge projecting radially inward from an interior surface of the liner; and angling the tubular body such that its axis is substantially directed towards a sound source.[%3] Clause 16. The method of any one or more of clauses 1-18, further comprising: inserting the microphone in a dead cat; and inserting the dead cat in the microphone cover apparatus.[%3] Clause 17. The method of any one or more of clauses 1-18, further comprising: wrapping the tubular body a pre-shell layer.[%3] Clause 18. The method of any one or more of clauses 1-18, wherein: the pre-shell layer is longer than the tubular body, forming a recess at an end of the pre-shell layer, and further comprising inserting a foam plug is into the recess.Interpretation[%3] References in the specification to "one embodiment", "an embodiment", etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded.[%3] It is further noted that the claims may be drafted to exclude any optional element or step. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as "solely," "only," and the like, in connection with the recitation of claim elements or use of a "negative" limitation. The terms "preferably," "preferred," "prefer," "optionally," "may," and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.[%3] The singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. The term "and / or" means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase "one or more" is readily understood by one of skill in the art, particularly when read in context of its usage.[%3] The term "about" can refer to a variation of ± 5%, ± 10%, ± 20%, or ± 25% of the value specified. For example, "about 50" percent can in some embodiments carry a variation from 45 to 55 percent. For integer ranges, the term "about" can include one or two integers greater than and / or less than a recited integer at each end of the range. Unless indicated otherwise herein, the term "about" is intended to include values and ranges proximate to the recited range that are equivalent in terms of the functionality of the composition, or the embodiment.[%3] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges recited herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof, as well as the individual values making up the range, particularly integer values. A recited range includes each specific value, integer, decimal, or identity within the range. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, or tenths. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc.[%3] As will also be understood by one skilled in the art, all language such as "up to", "at least", "greater than", "less than", "more than", "or more", and the like, include the number recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.[%3] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase "means for" or "step for". 

Claims

 1. A microphone cover apparatus, comprising:a tubular body, anda liner within the tubular body. 2. The apparatus of claim 1, further comprising:a ridge projecting radially inward from an interior surface of the liner.  3. The apparatus of claim 2, wherein:the ridge extends helically about a long axis of the body.  4. The apparatus of claim 2, wherein:the ridge is hollow. 5. The apparatus of claim 3, wherein:a helical length of the ridge is hollow.  6. The apparatus of claim 2, wherein:the ridge extends perpendicular to a long axis of the body.  7. The apparatus of claim 6, wherein:the ridge extends the entire inner circumference of the body. 8. The apparatus of claim 6, wherein:a second ridge is axially aligned with the ridge.  9. The apparatus of claim 6, wherein:a second ridge is radially aligned with the ridge. 10. The apparatus of claim 1, further comprising:a pre-shell layer around the tubular body. 11. The apparatus of claim 10, wherein the pre-shell layer is a neoprene layer.  12. The apparatus of claim 10, wherein:the pre-shell layer is axially longer than the tubular body, forming a recess at an end of the pre-shell layer; anda foam plug is disposed in the recess. 13. The apparatus of claim 1, further comprising:an outer shell, comprisinga hard tubular casing sized to enclose the tubular body therein; andan opening in the hard tubular casing, to allow sound to travel into the hard tubular casing's interior.  14. The apparatus of claim 13, wherein:the outer shell further comprisesa drainage hole, anda microphone wire hole.  15. A method of recording sound, the method comprising:disposing a microphone in a microphone cover apparatus, the microphone cover apparatus comprisinga tubular body, a liner within the tubular body, anda ridge projecting radially inward from an interior surface of the liner; andangling the tubular body such that its axis is substantially directed towards a sound source. 16. The method of claim 15, further comprising:inserting the microphone in a dead cat; andinserting the dead cat in the microphone cover apparatus. 17. The method of claim 15, further comprising:wrapping the tubular body a pre-shell layer. 18. The method of claim 17, wherein:the pre-shell layer is longer than the tubular body, forming a recess at an end of the pre-shell layer, andfurther comprising inserting a foam plug is into the recess.

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