This patent is related to U.S. patent application Ser. No. 13/654,225 by James Keith McElveen, filed on Oct. 17, 2012 and entitled “WEARABLE DIRECTIONAL MICROPHONE ARRAY APPARATUS AND SYSTEM,” assigned to the assignee of the present invention.
The presently claimed invention was made by or on behalf of the below listed parties to a joint research agreement. The joint research agreement was in effect on or before the date the claimed invention was made and the claimed invention was made as a result of activities undertaken within the scope of the joint research agreement. The parties to the joint research agreement are DANIEL TECHNOLOGY INC. and JAMES KEITH MCELVEEN.
The present invention is in the technical field of directional audio systems, in particular, microphone arrays used as directional audio systems and microphone arrays used as assisted listening devices and hearing aids.
Directional audio systems work by spatially filtering received sound so that sounds arriving from the look direction are accepted (constructively combined) and sounds arriving from other directions are rejected (destructively combined). Effective capture of sound coming from a particular spatial location or direction is a classic but difficult audio engineering problem. One means of accomplishing this is by use of a directional microphone array. It is well known by all persons skilled in the art that a collection of microphones can be treated together as an array of sensors whose outputs can be combined in engineered ways to spatially filter the diffuse (i.e. ambient or non-directional) and directional sound at the particular location of the array over time.
The prior art includes many examples of directional microphone array audio systems mounted as on-the-ear or in-the-ear hearing aids, eye glasses, head bands, and necklaces that sought to allow individuals with single-sided deafness or other particular hearing impairments to understand and participate in conversations in noisy environments. Among the devices proposed in the prior art is known as a cross-aid device. This device consists basically of a subminiature microphone located on the user's deaf side, with the amplified sound carried to the good ear. However, this device is ineffective when significant ambient or multi-directional noise is present. Other efforts in the prior art have been largely directed to the use of moving, rotatable conduits that can be turned in the direction that the listener wishes to emphasize (see e.g. U.S. Pat. No. 3,983,336). Alternatively, efforts have also been made in using movable plates and grills to change the acoustic resistance and thus the directive effect of a directional hearing aid (see e.g. U.S. Pat. No. 3,876,843 to Moen). Efforts have been made to increase directional properties, see U.S. Pat. No. 4,751,738 to Widrow and Bradley, and U.S. Pat. No. 5,737,430 to Widrow; however, these efforts display shortcomings in the categories of awkward or uncomfortable mounting of the microphone array and associated electronics on the person, hyper-directionality, ineffective directionality, inconsistent performance across sound frequencies, inordinate hardware and software complexity, and the like.
All of these prior devices allow in too much ambient and directional noise, instead of being focused more tightly on the desired sound source(s) and significantly reducing all off-axis sounds. This is largely due to their having beam widths so wide and side lobes so large that they captured much more than the desired sound source(s). In contrast, highly directional devices must have beam widths less than or equal to 25 degrees. In addition, prior art devices have had beam widths which varied significantly over frequency (making accurate steering more demanding) and lacked sufficient directivity gain due to the small number of microphones employed in general, and the limited effective aperture of the array.
As a result of these deficiencies, commercialized hearing aids, even augmented with prior microphone array technology, are considered ineffective by a majority of users in noisy and reverberant environments, such as restaurants, cocktail parties, and sporting events. What is needed, therefore, is a wearable directional microphone array capable of effectively filtering ambient and directional noise, while being comfortably and discreetly mounted on the user.
Several objects and advantages of the present invention are:
to allow construction of a highly directional audio array that is wearable, natural sounding, and convenient to direct;
to provide directional cues to users who have partial or total loss of hearing in one or both ears;
to simultaneously provide high gain, high directivity, high side lobe attenuation, and relatively consistent beam width;
to provide significant beam forming at lower frequencies where substantial noises are present, particularly in noisy, reverberant environments;
to allow construction of a body-worn or body-carried directional audio device that is cost effective.
Another object of the present invention is a wearable directional microphone array apparatus comprising an array of conductive fibers; a plurality of sensors connected to the array of conductive fibers; and, at least one output connector being operably engaged with the plurality of sensors through an electrical bus configured such that a first stage of beamformed audio is transferred from the at least one output connector to an electronics module.
Yet another object of the present invention is a wearable directional microphone array apparatus comprising a fabric mesh; a plurality of individually wired microphones coupled to the fabric mesh comprising an array panel; at least one output connector being operably engaged with the plurality of sensors through an electrical bus configured such that a first stage of beamformed audio is transferred from the at least one output connector to an electronics module.
Still yet another object of the present invention is a wearable directional microphone array system comprising a fabric mesh; a plurality of individually wired sensors coupled to the fabric mesh comprising an array; at least one output connector being operably connected to the plurality of sensors; an electronics module operably connected to the at least one output connector through an electrical bus; and, a garment being disposed upon the fabric mesh and the plurality of individually wired sensors.
Still further objects and advantages of this invention will become apparent from a consideration of the ensuing description and drawings.
Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following description of various embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well-known methods, procedures, protocols, services, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
As shown in
The construction details of the invention as shown in
Microphones 30, inter-panel connectors 12, output connector 13, and any other electronic components are typically mounted on one side of the PCB 14. The microphones 30 are typically arranged in what is known in some disciplines as a multiple-armed logarithmic spiral configuration with logarithmic spacing between the microphones. The microphones 30 are typically ported to the arriving sound pressure waves through tiny holes that go completely through the PCB 14, therefore the electronics are on one side of the array 10, while the smooth reverse side faces toward the sound source(s) of interest and helps minimizes mechanical rubbing noise against the fabric of the garment 24.
Other variations on this construction technique can be fabricated or easily conceived by any person skilled in the art, including but not limited to individually wired microphones arranged in the same or similar geometric pattern and mounted on or in a host device; substrates made of materials other than flexible PCB, such as hard PCB or even fabric with conductive wires, PCB traces, or other substances to electrically connect the microphones to the electronics module, power, and ground; other arrangements of microphones, such as fractal, equal, random, concentric circle, Golden Spiral, and Fibonacci spacing; and array panels 10 with vibration or sound absorbing layers of sound and vibration dampening materials (e.g. neoprene rubber or similar materials) on top and/or bottom.
Referring now to the invention shown in
In an embodiment, the construction details of the invention as shown in
Other variations on this construction technique include, but are not limited to, embedding the electronics contained in the electronics module inside of other housings or devices or directly on PCB 14; using digital electronics, including digital signal processors (DSPs), ASICs (application specific integrated circuits), FPGA (field programmable gate arrays) and similar technologies, to implement generally the same signal processing using digital devices as is being accomplished using analog and hybrid devices in an embodiment; and the use of other transducer types including but not limited to electret microphones, accelerometers, velocity transducers, acoustic vector sensors, and digital microphones (i.e. microphones with a digital output) instead of the current MEMS (micro-electromechanical systems) microphones with analog outputs.
In an embodiment, a multi-armed log spiral arrangement possesses a beam width of approximately 25 degrees across the system bandwidth; significant gain from 64 microphones; significant attenuation of the side lobes; and natural sounding quality of beamformed audio. In this embodiment, a user experiences optimal hearing quality in noisy, reverberant environments, including a narrow beam width across the system's frequency range; a relatively equal beam width across the system's frequency range; the optimal amount of gain and side lobe attenuation, and a natural quality to the resulting beamformed audio.
Referring now to the invention shown in
In an embodiment, the construction details of the invention as shown in
Referring now to the invention shown in
Other variations on this construction technique include adding successive stages of beamforming; alternative orders of filtering and gain control; use of reference channel signals with filtering to remove directional or ambient noises; use of time or phase delay elements to steer the directivity pattern; the separate beamforming of the two panels so that directional sounds to the left (right) are output to the left (right) ear to aid in binaural listening for persons with two-sided hearing or cochlear implant(s); and the use of one or more signal separation algorithms instead of one or more beamforming stages.
The advantages of the present invention include, without limitation,
(a) highly directional audio system as a body-worn or -carried assisted listening or hearing aid device;
(b) immunity to noises caused by RF interference and mechanical rubbing;
(c) low cost of construction;
(d) high reliability;
(e) tolerance to a wide range of temperature;
(f) light weight;
(g) simplicity of operation;
(h) simultaneous high gain, high directivity, and high side lobe attenuation; and
(i) low power consumption.
In an embodiment, the present invention is a directional microphone array used as wearable clothing or other body-worn or -carried assisted listening or hearing aid device.
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.
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Number | Date | Country |
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Entry |
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Khalil, Fadi, Jean Pascal Jullien, and André Gilloire, “Microphone array for sound pickup in teleconference systems.”, Journal of the Audio Engineering Society, 42, No. 9 (1994): 691-700. |
Number | Date | Country | |
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20150086039 A1 | Mar 2015 | US |
Number | Date | Country | |
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Parent | 13654225 | Oct 2012 | US |
Child | 14561433 | US |