CN101185369A - Wind noise rejection apparatus - Google Patents

Abstract

An apparatus for reduction of wind noise comprised of an electro-acoustic transducer arrangement with at least three bi-directional transducer elements disposed in three dimensions at an angle to each other and pointing towards a common sound source. The exposed structure is covered with a thin layer of acoustic-resistive material. The electrical outputs of the elements are added together to provide an output signal with increased signal to noise ratio.

Description

Wind noise rejection apparatus

Technical field

The present invention relates to the use of a kind of electroacoustic transducer (electro-acoustic transducers), particularly a kind of layout that under the situation of microphone, combines with the electronic circuit that reduces the wind noise effect.

Background technology

Wind noise problem about microphone is well-known, and has proposed a lot of solutions.Usually need in the scheme of these propositions to use complicated signal handling equipment, this has increased the cost of microphone very significantly.For example the simple scheme that certain deep bead is set for microphone also is suggested, and this scheme is effectively, still, and their heaviness very.

Summary of the invention

The invention provides a kind of electroacoustic transducer and arrange that this layout comprises three or more bi-directional transducer elements, these elements each other in the certain angle setting, and all point to common sound source substantially in three dimensions.The output of these elements is superimposed on together, thereby the output signal of the signal to noise ratio with increase is provided.

The invention has the advantages that, do not need to exist the sound source of expectation when the present invention works.

Description of drawings

In order to be more readily understood the present invention, with reference now to accompanying drawing, only the mode by example describes embodiments of the invention, wherein:

Fig. 1 schematically shows the microphone according to the first embodiment of the present invention;

Fig. 2 shows the block diagram of the circuit of the microphone that is used for Fig. 1;

Fig. 3 has schematically shown the two-dimensional phase diagonal angle between the purpose microphone that is used to explain;

Fig. 4 shows the block diagram that comprises another layout of improving circuit according to of the present invention.

Embodiment

Embodiments of the invention comprise at least three bi-directional transducer elements.Thereby being meant the barrier film that has front and back end ports in the enclosure and be provided with transducer in this shell, bi-directional transducer elements make barrier film be subjected to entering into the element of the sound wave influence in this shell by front and back end ports.For one embodiment of the present of invention, element is located relative to each other ideally, thereby makes that their front port is equidistant apart from the sound source of expectation, and the rear port that is projected in of the central axis of each element forms unique angle.In such layout, element can be positioned on the surface of imaginary ball, thereby makes their distance of sound source for equating apart from expectation.It is overlapping that the sensitivity of the front port of bi-directional microphones (sensibility) is tried one's best, and must lack and the sensitivity of rear port is overlapping, as shown in Figure 3 as far as possible.The sound source of expectation generally is positioned at the overlay region of front port, can obtain maximum gain at this place.The inhibition effect of wind noise can not influenced significantly by the direction that wind is moved.And the sound of expectation is positioned at the front of front port usually substantially, but this is not important.Microphone should not be installed in be generally used for will expectation sound focus in the hemisphere physically or parabola shaped device of common focus, because this can produce unacceptable leeway on front and back end ports, this leeway can weaken the inhibition of wind noise unfriendly.In another possible structure of three bi-directional microphones, the axis of each bi-directional microphones can be corresponding to three dimensions (X, Y, the vertical axis in each latitude Z), and therefore do not have two microphones to have common shaft angle.Microphone can be installed in the container of sealing and by cordonnier and expose.In addition, microphone should utilize thin anti-sound material to cover wind, this material can surround microphone or be placed on all microphones at least common expose the hole above.This material can be mat or to the similar sound sponge (acousticfoam) of sponge of the earphone that is used to cover head-telephone.Now the sensor element as microphone element is explained in more detail.

Bidirectional microphone elements preceding with after have identical sensitivity, and owing to the difference of the acoustic pressure of the front and back end ports that enters into element produces the signal of telecommunication.

With reference to figure 1, exist three bidirectional microphone elements, but these elements are not arranged to physically relative to each other in three dimensions and are pointed to common sound source, element B in Fig. 1 is with in D physically is arranged on identical plane, but the axle of element B and D points to the zone that comprises sound source substantially.In other words, the axis of two elements is in and still is in different angles in the same plane.Intermediary element C is physically located on the plane of element B and D, but tilts.Therefore, it is overlapping with the preceding polar response diagrams of element B and D basically that it points to the still preceding polar response diagrams (front polar response diagram) in the zone that comprises sound source.Therefore, utilize this layout, can obtain advantage of the present invention.

Turn to Fig. 2 now, can see, utilize this layout of microphone element, arithmetically the output stack with all microphone elements is possible.

Electricity output can utilize any suitable simulation or digital process (for example Digital Signal Processing) to be superimposed by any mode easily.

Although preferred embodiment has been utilized three bi-directional microphones, three or more microphones can use.Yet, exist restriction for the quantity of available microphone.Polar sensitivity figure referring now to the performance of the expression microphone element of measuring with full circle describes this restriction, but, it should be understood that in fact, arranges always three-dimensional rather than two dimension really.This is because wind can be from any direction in the three dimensions.As mentioned above, element is two-way.Therefore, the performance of each element is represented by the anterior-posterior polarity response diagram around axis.Sound source in the element distances expectation is under equidistant desirable situation, and preceding polar response diagrams can be overlapping on sizable degree.Yet back polar response diagrams is not overlapping ideally, and microphone element is provided with relative to each other realizes this.Therefore, the overlapping of sensitivity map is a factor of this restriction of microphone element quantity.Though top explanation supposition front port is equidistant apart from the sound source of expectation, and rear port has nonoverlapping polar response diagrams, and this can be similar to, and still can access the result of expectation simultaneously, and this will describe for Fig. 3.Consider that the 3rd microphone element is in perpendicular to the fact in the plane of paper, for brevity, the figure illustrates two microphone elements arbitrarily.

At first consider front port, i.e. those ports of the most close expectation sound source.Although on the principle, consistent thereby people place the focus of the geometric jacquard patterning unit surface that central axis that microphone element makes them is placed in theory with them ideally, in fact, all are needed to be that the polar sensitivity figure of front of element is overlapping substantially.Notice that polar sensitivity figure is representing three dimensions, as long as send in the space that the sound of expectation is the lap from each pole figure to be comprised, advantage of the present invention just can realize.Therefore, be apparent that also that the strict distance that equates not is necessary.The difference that can adapt to big degree, localized area or volume.

Further with reference to figure 3, what can notice is that bilateral element is positioned at the shell that is provided with anti-sound material or is formed by anti-sound material.Alternatively, bilateral element can be arranged in the housing with one or more holes, and in this case, only porose needs are coated with anti-sound material layer.Further, this material can be very thin kind, and for example usually relevant with earphone kind can't cause trouble to reality of the present invention like this.It should be noted, the equal opening of front and back end ports, and expose on the rear port sound, thereby axis is extended away from element in free space by front and back end ports.And, this being installed in physical hemisphere or the parabolic structure to focus on common ground with sound that will expectation be unallowed, this is because this will hinder the operation of rear port, influences wind noise suppression effect unfriendly.Although top embodiment discloses the use that is arranged on the lip-deep microphone element of imaginary ball, microphone element is arranged on any other the geometric imaginary surface with focus also is fine.Element can be set to matrix or criss-cross shape (cubical array) or as shown in fig. 1.

A kind of use of wanting is that microphone element is installed in some way, thereby makes cubical array be in relatively-stationary position with respect to the sound source of expectation.Be used at microphone under the situation of people's use, microphone can be connected to an end of boom (boom), and this boom self is the part of earphone or receiver.Selectively, microphone can be installed in the helmet, this helmet can have oxygen and supply with, play the effect of the inside sources of undesired wind noise, perhaps microphone can be used for replacing the existing microphone of existing external broadcasting layout, wherein microphone is positioned at retainer (cage), and this retainer is set up and remains against the user on the face, makes the certain distance of mouth of microphone self distance users.Application comprises and is used for the wired of mobile phone or bluetooth PHF (individual non-hand-held, personal hands free).Microphone can use with numeral or video frequency pick-up head, thereby makes the sound of expectation come from the roughly front of camera.The talker can be nonstatic or mobile, and can not influence the desired effects of wind noise suppression.

Should be emphasized that the microphone element that illustrates about Fig. 3 will improve any voice signal that sends from the represented zone of overlapping preceding polar response diagrams, whether the sound source of no matter expecting is physically located in this zone.Therefore, do not need about the exact position of microphone, and it has been found that, even the array of microphone element (as the explanation about Fig. 1 or 3) waves near suitable sound source with respect to mouth (speaking), thereby and can only receive from axis signal, element arrays also will work satisfactorily.

Fig. 1 is for explaining that it is useful that the circuit that is used for being provided by microphone arrangement optionally is out of shape.The wind direction represented by the direction of arrow among Fig. 1, and what can see is that microphone element B has self axis perpendicular to the wind direction.Therefore, the wind noise will act on the front and back end ports of element B with being equal to, and radially influence element B makes appropriate reaction to the sound in the zone of next self-contained sound source ability thus.Therefore, can this situation of electrical detection and restrain processedly from the signal of this element, the signal from element C and D is superimposed.In other words, be excluded from the signal of affected element, only the signal from the residue element is further processed.

Fig. 4 has shown the block diagram of the microphone array with the electronic circuit that is used to carry out inhibition above-mentioned and signal processing.There are a lot of other methods to be used to realize this purpose, utilize modeling scheme or utilize digital scheme.In the figure, shown microphone element B, C and D, and covered by the thin layer of common anti-sound sponge material 50.The output of element is fed into selector circuit 51, compares at 51 pairs of signals of this selector circuit, and suppresses signal from the most severe influenced element.Afterwards, signal is fed into level and frequency control circuit 52 (level and frequency controlcircuits), signal conditioning circuit 53 (signal conditioning circuits), be superimposed on then together, and treatment and supplied is used the bandpass filtering below the 200Hz to output 55 in filter circuit 54 in filter circuit 54.Other fluting or band-pass filter can be provided, be used for compensating less for the shading of low frequency of voiceband.

The array of microphone element has replaced traditional microphone, thereby and thus can be by be attached to the direct replacement that is used as this kind microphone in the equipment in manufacture process.This can by in manufacture process with microphone element and relevant signal adder circuit combination, realize as the parts of large equipment more.Alternatively, microphone element can encapsulate in the mode easily that has or the signal adder circuit not relevant with them like this and offer manufacturer as module.Microphone element can be installed with suitable relative to each other angle and correct orientation by using overmolded (over-molded) high temperature polymer.What need take care is to guarantee that rear port is straightway and guarantees that front port is mounted structure influence to the blast of rear port minimumly.In addition, mounting structure should make the variable effect of direction of the wind that the direction of the wind that obtained by a microphone is obtained with respect to other microphone minimize.In other words, all microphone should detect the wind from identical general direction.

Bi-directional transducer elements array (no matter whether being modular form) can be installed in the enclosure, and this shell can be a waterproof, but is provided with the perforation array that is coated with anti-sound material thin-layer.Shell can be provided with and be used for element arrays is connected to device on another part equipment of user, for example passes through spring clip.The present invention has widely as the parts of large equipment spare part or as the module of large equipment and uses.In order to provide some explanations of various application, multiple different execution mode will be described now.This is not the tabulation of exhaustive.

A kind of execution mode is to be used to replace the external broadcasting microphone, as previously mentioned.Another kind of execution mode is microphone or the interior individual non-hand-held external member part of mobile phone that replaces in the mobile phone.Another kind of execution mode is the microphone that replaces in the potable recording device.

Another kind of execution mode is the microphone that replaces in digital camera or video frequency pick-up head, video frequency pick-up head-phone or other portable communication apparatus.Thereby this can be to make any microphone that the user talks facing to the user under the scene of taking a picture.Although top layout all is with reference to wind and microphone and be disclosed, identical principle also can be used in other fluid, water for example, and in this case, transducer is commonly referred to as detectoscope.

Further, bi-directional transducer elements can utilize the semiconductor technology that allows element arrays to take little space to make.Sometimes the MEMs microphone that is called as SiMIC (silicon microphone) need increase metapore, can realize the amphicheirality.

Use is in the miniature bidirectional microphone elements of suitable array, allows form of the present invention to be used in to be suitable in the hearing aids under outdoor and gentle breeze or the wind conditions.

Although top description is meant the use of bilateral element, it should be noted that because the omnidirectional microphone element also has identical characteristic, so omnidirectional microphone also can use, but effect can be little a lot.

Claims (19)

1. an electroacoustic transducer is arranged, the sensor element that comprises the rear port of at least three front ports with opening and opening, the line of front and back end ports that these at least three sensor elements are arranged to make each element relatively mutually in three-dimensional mutually at an angle, and point to common sound zone substantially, the device that has the output that is used for receiving element and be used for output is superimposed, and thin anti-sound material, this thin anti-sound material covers at least a portion that all the sensors is exposed to the common space of wind.

2. transducer arrangements as claimed in claim 1, wherein, described sensor element is arranged in the array that forms imaginary ball or parabolical part.

3. transducer arrangements as claimed in claim 1 or 2, wherein, described element is a microphone element, and is positioned on the microphone suspension bracket that is connected to user's head, thus the mouth of directed towards user is located.

4. transducer arrangements as claimed in claim 1 or 2, wherein, described element is a microphone element, and is positioned on the helmet, thus the mouth of directed towards user.

5. as each described transducer arrangements in the claim 1 to 4, wherein, described element is installed with suitable angle and orientation by the high temperature polymer that uses overmolded, and the high temperature polymer of this overmolded is placed by the SMT technology of standard.

6. as each described transducer arrangements in the claim 1 to 5, wherein, a plurality of elements utilize the manufacturing of semiconductor microactuator manufacturing technology.

7. as each described transducer arrangements in the claim 1 to 6, wherein, each in the sensor element is a bilateral element.

8. a sensor assembly comprises shell, is provided with as described above each described transducer arrangements in the claim in this shell, and wherein, the outer surface of described shell is semi permeable and is waterproof in a direction.

9. module as claimed in claim 8, wherein, the perforation array is adjacent to be arranged in the described waterproof case with each microphone.

10. module as claimed in claim 9, this module is adjustable on all in-planes perpendicular to the microphone face, described orientation is adjustable fully, and utilizes enough frictions self-align.

11. as each described module in the claim 8,9 or 10, wherein, erecting device is with the form setting of overmolded encapsulation.

12. module as claimed in claim 8, wherein, described waterproof material is connected to the rear portion of microphone package and forms oval-shaped center, and this oval-shaped center is in the space of every other point.

13. module as claimed in claim 8, wherein, described shell is provided with flexible fastening back splint.

14. as each described module in the claim 8 to 13, wherein, electrical connection and described transducer arrangements electrically go up to be guaranteed in another equipment.

15. a camera is combined with as described above each described transducer arrangements in the claim.

16. a portable communication apparatus is combined with as each described transducer arrangements or module in the claim 1 to 14.

17. portable communication apparatus as claimed in claim 16, wherein, described device transmits data and sound.

18. a hearing aids is combined with transducer arrangements as claimed in claim 6.

19. a tape deck is combined with as each described transducer arrangements or module in the claim 1 to 13.

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