Patent Application
20110164759
The technical field generally relates to a mounting arrangement for microphones.
Many current vehicles in the marketplace are equipped with communication equipment that enables a vehicle occupant to engage in verbal communications with remotely located entities such as a call center and/or other parties. In some cases, the communication equipment uses voice recognition software to permit the vehicle occupant to give verbal commands to control the communication equipment itself and/or other equipment in the vehicle. Accordingly, the communication equipment typically includes a microphone to facilitate the vehicle occupant's uses of the communication equipment.
It has been observed that as the frequency of a human voice increases, the effectiveness of some microphones to receive the human voice diminishes. It has been determined that wideband microphones are more effective than non-wideband microphones at receiving human voices at higher frequencies. In some instances, it has been observed that a wideband microphone provides a 2-3% improvement over non-wideband microphones when receiving high frequency voice transmissions in conjunction with voice recognition software.
It is also known that the use of microphones that are designed to be relatively highly receptive to sound energy in a predetermined direction can further assist in receiving high frequency human voice transmissions. Such microphones are commonly known as directional microphones. The direction of a directional microphone's relatively high receptivity to sound energy will be referred to herein as the “acoustic axis” of the directional microphone.
When a directional wideband microphone is used in conjunction with the communication equipment discussed above, the directional microphone is typically mounted within a housing and is oriented so that the acoustic axis extends in a direction generally transverse to the housing. Once positioned in the housing, a sound isolating member is typically positioned over the directional microphone. The sound isolating member is configured to redirect the acoustic axis of the directional microphone so that the acoustic axis extends in a desired direction.
It has been observed that some mounting arrangements used to mount directional wideband microphones to an interior surface of a vehicle, including some which employ the sound isolating member described above, can adversely affect the directional wideband microphone's ability to receive high frequency voice transmissions, and thus negate or diminish the benefits derived from the use of a wideband microphone.
Accordingly, a mounting arrangement that does not significantly diminish a directional wideband microphone's ability to receive high frequency voice transmissions is desirable. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
An arrangement and method are provided for mounting a microphone to a surface in a passenger compartment of a vehicle. In a first, non-limiting example, an arrangement includes, but is not limited to, a housing having an opening. The housing is configured to be mounted to the surface. A directional wideband microphone is mounted within the housing and positioned to partition the housing into a first chamber and a second chamber. The directional wideband microphone has an acoustic axis that extends through the first chamber. In this first non-limiting example, the housing and the directional wideband microphone cooperate to direct the acoustic axis in a predetermined direction.
In a second, non-limiting example, an arrangement includes, but is not limited to, a housing having an opening. The housing is configured to be mounted to the surface. A directional wideband microphone is mounted within the housing and is positioned to partition the housing into a first chamber and a second chamber. The directional wideband microphone has an acoustic axis that extends through the first chamber. The directional wide band microphone is positioned a distance from a far wall of the first chamber that is less than a length of a wavelength of a frequency of interest. In this second non-limiting example, the housing and the directional wideband microphone cooperate to direct the acoustic axis in a predetermined direction.
In a third, non-limiting example, an arrangement includes, but is not limited to, a housing having an opening. The housing is configured to be mounted to the surface. A directional wideband microphone is mounted within the housing and is positioned to partition the housing into a first chamber and a second chamber. The directional wideband microphone has an acoustic axis that extends through the first chamber. The directional wide band microphone is positioned a distance from a far wall of the first chamber that is less than a length of a wavelength of a frequency of interest. A mass of sound absorbing material is disposed in the front chamber. In this third non-limiting example, the housing and the directional wideband microphone cooperate to direct the acoustic axis in a predetermined direction.
One or more examples will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
In some non-limiting examples, it may be desirable for a directional microphone to have a frequency response that goes from 300 Hz to 8000 Hz with a variance of less than 2 dB per octave while preserving its directional properties throughout the entire range. In other examples, different ranges and/or different variances may be desirable. Regardless of specific performance goals and specifications, the diminution of a directional wideband microphone's high frequency voice transmission receptivity (hereinafter, “high frequency receptivity”) can be at least partially offset by configuring the arrangement that is used to mount the microphone to a surface in a manner that enhances the high frequency receptivity of the microphone. For example, the sound isolating member which is used in prior art arrangements to focus the acoustic axis of the directional wideband microphone may be removed. Removal of the sound isolating member eliminates a source of high frequency interference which causes a diminution in the high frequency receptivity of the directional wideband microphone. A vibration isolating member, or boot, may at least partially surround the directional wideband microphone to further prevent high frequency interference. The directional wideband microphone may further be mounted in a housing and oriented with respect to the housing such that the acoustic axis is directed by the directional wideband microphone to extend in a direction that is substantially parallel to a surface of the housing. The directional wideband microphone and the housing will then cooperate to angle or deflect the acoustic axis in a desired direction. In some examples, it may be desirable to direct the acoustic axis to extend towards an occupant of a vehicle in which the directional wideband microphone is mounted. In some examples, the housing and the directional wideband microphone may cooperate to direct the acoustic axis toward a mouth of the occupant.
In some examples, the directional wideband microphone may be mounted to, and electrically connected to, a preamplifier. In some examples, the preamplifier may be positioned above the directional wideband microphone to minimize high frequency interference with the directional wideband microphone. In other examples, the preamplifier may be built into the microphone.
In still other examples, the directional wideband microphone may be mounted to the housing in an orientation that is oblique with respect to the surface of the housing or may otherwise be mounted in a manner that causes the directional wideband microphone to direct the acoustic axis to extend at an angle that is oblique with respect to the surface of the housing. When mounted in an overhead console or headliner of a vehicle, mounting the directional wideband microphone in an oblique manner permits the housing and the directional wideband microphone to cooperate to deflect the acoustic axis further than the deflection caused when the directional wideband microphone directs the acoustic axis to extend in a substantially parallel direction with respect to the surface of the housing. This may be desirable in vehicles where the driver sits close to the directional wideband microphone. In such circumstances, it may be desirable to have a higher degree of deflection to direct the acoustic axis towards the driver's mouth. In each of the arrangements discussed above, the wideband frequency response of the microphone is not altered by the housing. This is due, in part, to the omission of the sound isolating member discussed above.
A greater understanding of the examples of the apparatus disclosed herein may be obtained through a review of the illustrations accompanying this application together with a review of the detailed description that follows.
With reference to
Vehicle 12 may be any type of mobile vehicle such as a motorcycle, car, truck, recreational vehicle (RV), boat, plane, etc., and is equipped with suitable hardware and software that enables it to communicate over communication system 10. Some of the vehicle hardware 20 is shown generally in
The telematics unit 24 is an onboard device that provides a variety of services through its communication with the call center 18, and generally includes an electronic processing device 38, one or more types of electronic memory 40, a cellular chipset/component 34, a wireless modem 36, a dual mode antenna 70, and a navigation unit containing a GPS chipset/component 42. In one example, the wireless modem 36 includes a computer program and/or set of software routines adapted to be executed within electronic processing device 38.
The telematics unit 24 may provide various services including: turn-by-turn directions and other navigation-related services provided in conjunction with the GPS based chipset/component 42; airbag deployment notification and other emergency or roadside assistance-related services provided in connection with various crash and/or collision detection sensor interface modules 66 and collision sensors 68 located throughout the vehicle; and/or infotainment-related services where music, Internet web pages, movies, television programs, videogames, and/or other content are downloaded by an infotainment center 46 operatively connected to the telematics unit 24 via vehicle bus 32 and audio bus 22. In one example, downloaded content is stored for current or later playback. The above-listed services are by no means an exhaustive list of all the capabilities of telematics unit 24, but are simply an illustration of some of the services that the telematics unit may be capable of offering. It is anticipated that telematics unit 24 may include a number of additional components in addition to and/or different components from those listed above.
Vehicle communications may use radio transmissions to establish a voice channel with wireless carrier system 14 so that both voice and data transmissions can be sent and received over the voice channel. Vehicle communications are enabled via the cellular chipset/component 34 for voice communications and the wireless modem 36 for data transmission. In order to enable successful data transmission over the voice channel, wireless modem 36 applies some type of encoding or modulation to convert the digital data so that it can be communicated through a vocoder or speech codec incorporated in the cellular chipset/component 34. Any suitable encoding or modulation technique that provides an acceptable data rate and bit error can be used with the present examples. Dual mode antenna 70 services the GPS chipset/component 42 and the cellular chipset/component 34.
Microphone 26 provides the driver or other vehicle occupant with a means for inputting verbal or other auditory commands, and can be equipped with an embedded voice processing unit utilizing a human/machine interface (HMI) technology known in the art. Conversely, speaker 28 provides audible output to the vehicle occupants and can be either a stand-alone speaker specifically dedicated for use with the telematics unit 24 or can be part of a vehicle audio component 64. In either event, microphone 26 and speaker 28 enable vehicle hardware 20 and call center 18 to communicate with the occupants through audible speech. The vehicle hardware also includes one or more buttons and/or controls 30 for enabling a vehicle occupant to activate or engage one or more components of the vehicle hardware 20. For example, one of the buttons and/or controls 30 can be an electronic pushbutton used to initiate voice communication with call center 18 (whether it be a human such as advisor 58 or an automated call response system). In another example, one of the buttons and/or controls 30 can be used to initiate emergency services.
The vehicle audio component 64 is operatively connected to the vehicle bus 32 and the audio bus 22. The vehicle audio component 64 receives analog information, rendering it as sound, via the audio bus 22. Digital information is received via the vehicle bus 32. The vehicle audio component 64 provides amplitude modulated (AM) and frequency modulated (FM) radio, compact disc (CD), digital video disc (DVD), and multimedia functionality independent of the infotainment center 46. Vehicle audio component 64 may contain a speaker system, or may utilize speaker 28 via arbitration on vehicle bus 32 and/or audio bus 22.
The vehicle crash and/or collision detection sensor interface modules 66 is operatively connected to the vehicle bus 32. The collision sensors 68 provide information to the telematics unit via the crash and/or collision detection sensor interface modules 66 regarding the severity of a vehicle collision, such as the angle of impact and the amount of force sustained.
Vehicle sensors 72, connected to various sensor interface modules 44 are operatively connected to the vehicle bus 32. Example vehicle sensors include but are not limited to gyroscopes, accelerometers, magnetometers, emission detection, and/or control sensors, and the like. Example sensor interface modules 44 include powertrain control, climate control, and body control, to name but a few.
Wireless carrier system 14 may be a cellular telephone system or any other suitable wireless system that transmits signals between the vehicle hardware 20 and land network 16. According to an example, wireless carrier system 14 includes one or more cell towers 48, base stations and/or mobile switching centers (MSCs) 50, as well as any other networking components required to connect the wireless carrier system 14 with land network 16. As appreciated by those skilled in the art, various cell tower/base station/MSC arrangements are possible and could be used with wireless carrier system 14. For example, a base station and a cell tower could be co-located at the same site or they could be remotely located, and a single base station could be coupled to various cell towers or various base stations could be coupled with a single MSC, to list but a few of the possible arrangements. A speech codec or vocoder may be incorporated in one or more of the base stations, but depending on the particular architecture of the wireless network, it could be incorporated within a Mobile Switching Center or some other network components as well.
Land network 16 can be a conventional land-based telecommunications network that is connected to one or more landline telephones, and that connects wireless carrier system 14 to call center 18. For example, land network 16 can include a public switched telephone network (PSTN) and/or an Internet protocol (IP) network, as is appreciated by those skilled in the art. Of course, one or more segments of the land network 16 can be implemented in the form of a standard wired network, a fiber or other optical network, a cable network, other wireless networks such as wireless local networks (WLANs) or networks providing broadband wireless access (BWA), or any combination thereof.
Call center 18 is designed to provide the vehicle hardware 20 with a number of different system back-end functions and, according to the example shown here, generally includes one or more switches 52, servers 54, databases 56, advisors 58, as well as a variety of other telecommunication/computer equipment 60. These various call center components are suitably coupled to one another via a network connection or bus 62, such as the one previously described in connection with the vehicle hardware 20. Switch 52, which can be a private branch exchange (PBX) switch, routes incoming signals so that voice transmissions are usually sent to either the live advisor 58 or an automated response system, and data transmissions are passed on to a modem or other piece of equipment 60 for demodulation and further signal processing. The modem 60 may include an encoder, as previously explained, and can be connected to various devices such as a server 54 and database 56. For example, database 56 could be designed to store subscriber profile records, subscriber behavioral patterns, or any other pertinent subscriber information. Although the illustrated example has been described as it would be used in conjunction with a manned call center 18, it will be appreciated that the call center 18 can be any central or remote facility, manned or unmanned, mobile or fixed, to or from which it is desirable to exchange voice and data.
Vehicle 12 may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD). Although an automobile is depicted in
Interior 74 includes a rear view mirror 76 that permits a driver of vehicle 12 to observe traffic and other conditions located to the rear of vehicle 12. Buttons and/or controls 30 (see
Vehicle 12 includes an overhead console 78 mounted to an upper surface of interior 74. In some examples, overhead console 78 may be mounted to a headliner. In other examples, overhead console 78 may be mounted to a roof portion of vehicle 12, or to any other suitable surface. Overhead consoles such as overhead console 78 may provide a wide variety of features and/or components including, without limitation, internal rear view mirrors, eyeglass holders, reading lights, universal garage door openers, storage compartments, and the like. In some examples, a microphone assembly 80 may be mounted to, or within, overhead console 78. Such mounting may be accomplished through the use of mechanical fasteners, threaded fasteners, adhesives, epoxies, welds, snap fit arrangements, or through any other means or combination of means effective to mount microphone assembly 80 to overhead console 78. It should be understood that, although the arrangements for mounting a microphone discussed and illustrated herein are shown and discussed in conjunction with mounting a microphone to an overhead console, the arrangements disclosed herein are compatible with other surfaces and/or components.
In the illustrated example, microphone assembly 80 houses directional wideband microphone 82 and may be used by a driver or other occupant of vehicle 12 to verbally communicate with an advisor 58 at call center 18 and/or to interact with telematics unit 24, or with other portions of the vehicle hardware 20. In the illustrated example, overhead console 78 and microphone assembly 80, are positioned generally in an area above, and forward of, a location where the driver of vehicle 12 is expected to sit.
With respect to
Overhead console 78 includes an integral grill 81 adjacent to an area where microphone assembly 80 resides in order to permit sound to enter microphone assembly 80. In some examples, grill 81 may be acoustically transparent. As used herein, the term “acoustically transparent” when used in conjunction with a structure shall refer to a structure having one or more openings passing through solid portions of the structure wherein the ratio of open area to solid area is sufficient to permit the transmission of audible sound energy through the structure without any diminution in audibility. In other examples, grill 81 may not be integral with overhead console 78 but instead may be fabricated separately and attached to overhead console 78 in any manner effective to provide a secure attachment.
With respect to
In the illustrated example, housing 84 has a generally rectangular configuration and a central axis A-A. In other examples, other suitable configurations may be employed. In some examples, housing 84 may need to be constructed in accordance with previously existing specifications to provide backwards compatibility with existing microphone assembly mounts.
In the illustrated example, housing 84 includes a pair of oppositely disposed snap-fit features 88. Snap-fit features 88 are configured to engage a snap fit mount integrated into, or attached to, overhead console 78. In other examples, the pair of snap-fit features 88 may be disposed on other surfaces of housing 84. In still other examples, a greater or lesser number of snap-fit features 88 may be employed. In other examples, any suitable attachment means may be employed.
Housing 84 includes a mounting surface 90. Mounting surface 90 serves as the ceiling of housing 84 and is generally co-planar with central axis A-A. Housing 84 further includes a pair of oppositely disposed walls 92 which are attached to opposite ends of mounting surface 90 and which are disposed generally transverse to mounting surface 90.
A preamplifier 94 is attached to mounting surface 90. Preamplifier 94 serves to amplify low level audio signals. Preamplifier 94 may be attached to mounting surface 90 in any suitable manner including, without limitation, through the use of adhesives, welds, threaded fasteners and mechanical fasteners. In other examples, discussed below, preamplifier 94 may be attached elsewhere.
A microphone sub-assembly 96 is mounted to preamplifier 94 and is electrically connected thereto. In other examples, microphone sub-assembly 96 may be mounted to housing 84 and electrically connected to preamplifier 94. In the example illustrated in
Microphone sub-assembly 96 further includes a vibration isolating member or boot 100. Boot 100 may be made from rubber materials, plastic materials, elastomeric materials and/or any other materials effective to permit boot 100 to isolate directional wideband microphone 98 from vibrations. In the illustrated example, and as best seen in
Microphone sub-assembly 96 is positioned within, and mounted to, housing 84 in a manner that partitions housing 84 into a first chamber 99 and a second chamber 101. A first opening 85 allows sound to enter first chamber 99. A second opening 87 allows sound to enter second chamber 101. In some examples, microphone sub-assembly 96 substantially seals first chamber 99 from second chamber 101 to substantially obstruct the direct transmission of sound between the two chambers. It has been observed that when the volume of first chamber 99 is substantially equal to the volume of second chamber 101, the frequency response of directional wideband microphone 98 is substantially unaltered.
In the example in
Because directional wideband microphone 98 is disposed within housing 84 in a manner such that substantially all portions of directional wideband microphone 98 are positioned above lower surfaces of walls 92, housing 84 cooperates with directional wideband microphone 98 to deflect acoustic axis 102 in a downward direction, resulting in acoustic axis 104. When microphone assembly 80 is mounted in overhead console 78, downwardly extending acoustic axis 104 extends towards a driver of vehicle 12. In some examples, the downward deflection of acoustic axis 102 permits acoustic axis 104 to point or extend toward a mouth of a person driving vehicle 12. Exclusion of the sound isolating member, discussed above in the background section, helps to avoid alteration of the frequency response of directional wideband microphone 98.
An acoustic textile 106 is positioned over first and second openings 85, 87, and in this manner, is disposed between directional wideband microphone 98 and sources of sound. Acoustic textile 106 impedes the flow of sound waves through first and second openings 85, 87. Acoustic textile 106 removes sound energy from sound waves as they pass through first and second openings 85, 87 and converts the sound energy to some other form of energy, for instance, heat or mechanical energy. The material comprising acoustic textile 106 may be selected based on its acoustic impedance. A material's acoustic impedance equals the density of the material multiplied by the material's speed of sound. Based on the material selected, the acoustic textile can be tuned to filter out, or otherwise diminish, sound waves of a particular frequency. In this manner, if the directional wideband microphone has an elevated sensitivity or an otherwise undesired response to sound of a particular frequency, acoustic textile 106 can muffle or diminish the strength of the sound waves of that particular frequency before they reach directional wideband microphone 98 and thus contribute to a wideband microphone's generally flat response across its entire frequency bandwidth. Additionally, acoustic textile 106 is porous to permit sound to pass through it. The porosity of acoustic textile 106 need not be uniform. Rather, the porosity of acoustic textile 106 may vary throughout the material. By varying its porosity, acoustic textile 106 may be used to tune the frequency response of directional wideband microphone 98. Acoustic textile 106 may also serve generally as a cover to protect microphone sub-assembly 96 from dust, spills, debris or other items.
A mass 107 of sound absorbing material is illustrated in first chamber 99. Mass 107 acts as an acoustic resistance and attenuates any standing waves in an enclosed volume. An increase in the mass of mass 107 will decrease a resonance frequency inherent within first chamber 99 and serves to attenuate any elevations in the frequency response of directional wideband microphone 98. Mass 107 may comprise a foam material. A wide variety of different foams may be used. The different densities and porous textures of differing foam materials act at specific frequencies. Mass 107 may have any suitable shape and may have any suitable density. An appropriate shape and density utilized for a particular application may be arrived at through a process of trial and error, with different shapes and different densities being tested until a desired frequency response for directional wideband microphone 98 is obtained. In other examples, a second mass of sound absorbing material may also be positioned in second chamber 101.
With respect to
It has further been observed that when L1 is less than a length of a wavelength of interest, the frequency response of directional wideband microphone 98 is substantially unaltered. As used herein, the term “wavelength of interest” refers to the wavelength of sound having the highest frequency that is desired to be detected by directional wideband microphone 112. The higher the frequency, the shorter the wavelength. A single period of wavelength of Interest, WLI, is illustrated in
An alternate example of a microphone sub-assembly made in accordance with the teachings of the present disclosure is illustrated in
Preamplifier 110 is configured to be electrically connected to directional wideband microphone 112 via leads or wires 116. Directional wideband microphone 112 includes receivers 118 to receive leads or wires 116. In other examples, preamplifier 110 may plug into directional wideband microphone 112 with rigid prongs or in any other suitable manner that permits the electrical connection between directional wideband microphone 112 and preamplifier 110 to serve as the mechanical connection between these components.
Directional wideband microphone 112 includes two sound receiving portions 120 on a rear facing surface of directional wideband microphone 112. In other examples, a greater or lesser number of sound receiving portions 120 may be disposed on the rear facing surface of directional wideband microphone 112. These sound receiving portions 120 permit sound to enter a rear portion of directional wideband microphone 112 and through the use of well known noise cancellation techniques, allow directional wideband microphone 112 to have directional listening capabilities.
With respect to
With respect to
With respect to
At step 128, the microphone is connected to the housing such that the housing and the microphone cooperate to unilaterally direct the acoustic axis in a desired direction and such that the housing does not alter the frequency response of the microphone. In some examples, the microphone may be connected to the housing such that the microphone directs the acoustic axis to extend in a direction that is substantially parallel to a central axis of the housing. In other examples, the microphone may be connected to the housing such that the microphone directs the acoustic axis to extend in a direction that is oblique to the central axis of the housing.
At step 130, the housing, with the microphone connected, is attached to a surface in a vehicle. For example, the housing may be pushed into position and mounted in a snap-fit fashion within an overhead console such as overhead console 78. In other examples, the housing may be screwed, bolted, or riveted into position. In other examples, the housing may be attached by adhesives or epoxies. In still other examples, the housing may be welded into position. In still other examples, any technique or fastener effective to mount the housing to the surface may be employed.
While at least one example has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the example or examples are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the example or exemplary examples. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope as set forth in the appended claims and the legal equivalents thereof.
