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AU703296B2 - Loudspeakers comprising panel-form acoustic radiating elements - Google Patents

Loudspeakers comprising panel-form acoustic radiating elements Download PDF

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Publication number
AU703296B2
AU703296B2 AU68814/96A AU6881496A AU703296B2 AU 703296 B2 AU703296 B2 AU 703296B2 AU 68814/96 A AU68814/96 A AU 68814/96A AU 6881496 A AU6881496 A AU 6881496A AU 703296 B2 AU703296 B2 AU 703296B2
Authority
AU
Australia
Prior art keywords
panel
radiator
form loudspeaker
loudspeaker according
frame
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
AU68814/96A
Other versions
AU6881496A (en
Inventor
Henry Azima
Martin Colloms
Neil Harris
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NVF Tech Ltd
Original Assignee
New Transducers Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=34865245&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=AU703296(B2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from GBGB9517918.0A external-priority patent/GB9517918D0/en
Priority claimed from GBGB9522281.6A external-priority patent/GB9522281D0/en
Priority claimed from GBGB9606836.6A external-priority patent/GB9606836D0/en
Application filed by New Transducers Ltd filed Critical New Transducers Ltd
Publication of AU6881496A publication Critical patent/AU6881496A/en
Application granted granted Critical
Publication of AU703296B2 publication Critical patent/AU703296B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00Diaphragms for electromechanical transducers; Cones
    • H04R7/02Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04Plane diaphragms
    • H04R7/045Plane diaphragms using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2440/00Bending wave transducers covered by H04R, not provided for in its groups
    • H04R2440/07Loudspeakers using bending wave resonance and pistonic motion to generate sound

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)

Abstract

A panel-form loudspeaker (81) comprising a resonant distributed mode acoustic radiator having a periphery, a transducer (9) mounted to the radiator to excite distributed mode resonance in the radiator, and a frame (1) supporting the radiator, the transducer being coupled between the radiator and the frame to vibrate the panel to cause it to resonate to produce an acoustic output, characterised in that frame supports the radiator round its periphery and by resilient suspension means coupled between the frame and the radiator periphery.

Description

WO 97/09845 PCT/GB96/02158 1
TITLE:
LOUDSPEAKERS COMPRISING PANEL-FORM ACOUSTIC RADIATING
ELEMENTS
DESCRIPTION
TECHNICAL FIELD The invention relates to loudspeakers and more particularly to loudspeakers comprising panel-form acoustic radiating elements.
BACKGROUND ART It is known from GB-A-2262861 to suggest a panel-form loudspeaker comprising:a resonant multi-mode radiator element being a unitary sandwich panel formed of two skins of material with a spacing core of transverse cellular construction, wherein the panel is such as to have ratio of bending stiffness in all orientations, to the cube power of panel mass per unit surface area of at least a mounting means which supports the panel or attaches 2 to it a supporting body, in a free undamped manner; and an electro-mechanical drive means coupled to the panel which serves to excite a multi-modal resonance in the radiator panel in response to an electrical input within a working frequency band for the loudspeaker.
US-A-3,247,925 of WARNAKA discloses what purports to be a low frequency resonant panel loudspeaker mounted in a chassis and excited by an electromechanical transducer mounted on the chassis.
DISCLOSURE OF INVENTION Embodiments of the present invention use members of nature, structure and configuration achievable generally and/or specifically by implementing teachings of our copending PCT publication No. W97/09842 of even date herewith. Such members thus have capability to sustain and propagate input vibrational energy by bending waves in operative area(s) extending transversely of thickness often but not necessarily to edges of the member(s); are configured with or without anisotropy of bending stiffness to have resonant mode vibration components distributed over said area(s) beneficially for acoustic coupling with ambient air; and have predetermined preferential locations or sites within said area for transducer means, particularly operationally active or moving part(s) thereof effective in relation to acoustic vibrational activity in said area(s) and signals, usually electrical, corresponding to acoustic content of such vibrational activity. Uses are envisaged in co-pending International publication No.
AMENDED SHEET 2a W097/09842 of even date herewith for such members as or in "passive" acoustic devices without transducer means, such as for reverberation or for acoustic filtering or for acoustically "voicing" a space or room; and as or in SAMENDED
SHEET
3 "active" acoustic devices with transducer means, such as in a remarkably wide range of sources of sound or loudspeakers when supplied with input signals to be converted to said sound, or in such as microphones when exposed to sound to be converted into other signals.
This invention is particularly concerned with active acoustic devices in the form of loudspeakers.
Members as above are herein called distributed mode acoustic radiators and are intended to be characterised as in the above PCT application and/or otherwise as specifically provided herein.
The invention is a panel-form loudspeaker comprising a member having a periphery and having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness to have resonant mode vibration components distributed over said at least one area and have predetermined preferential locations or sites within said area for transducer means and having a transducer mounted on said member at one of said locations or sites to vibrate the member to cause it to resonate forming an acoustic radiator which provides an acoustic output when resonating, a frame supporting the radiator round its periphery, the transducer being coupled between the radiator and the frame and resilient suspension means coupled between the frame, and the radiator periphery whereby the radiator is capable of pistonic movement and resonant behaviour, and wherein the transducer is adapted to move the radiator
SHEET
4 Q l a I pistonically. The frame may have a portion surrounding the radiator. The resilient suspension may be of an elastomeric material. The frame may comprise a floor stand having a ground engaging portion, a substantially upright portion extending from the ground engaging portion and a plurality of arms extending from the upright portion, the distal ends of which arms connect to the frame portion surrounding the radiator. The radiator may be rectangular, and the arms may extend near to the corners of the radiator. The transducer may be mounted on or adjacent to the upright portion of the frame. The transducer may be mounted on a lug projecting from the upright portion. A balancing pair of transducers may be provided. The radiator may comprise a lightweight core separating a pair of high modulus lightweight skins.
BRIEF DESCRIPTION OF DRAWINGS The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which:- Figure 1 is a diagram showing a distributed-mode loudspeaker as described and claimed in our co-pending International publication No. W097/09842; Figure 2a is a partial section on the line A-A of Figure 1; Figure 2b is an enlarged cross-section through a distributed mode radiator of the kind shown in Figure 2a and showing two alternative constructions; Figure 3a is a front view of an embodiment of distributed-mode loudspeaker according to the present
~CE
0 4a invention; Figure 3b is a side view of the distributed-mode loudspeaker of Figure 3a, and Figure 3c is a rear view of the loudspeaker of Figure 3a.
BEST MODES FOR CARRYING OUT THE INVENTION Referring to Figure 1 of the drawings, there is shown a panel-form loudspeaker (81) of the kind described and claimed in our co-pending International publication No.
W097/09842 of even date herewith comprising a rectangular frame carrying a resilient suspension round its inner periphery which supports a distributed mode sound radiating panel A transducer e.g as described in detail with reference to our co-pending International publication Nos. W097/09859, W097/09861, W097/09858 of even date herewith, is mounted wholly and exclusively on or in the panel at a predetermined location defined by dimensions x and y, the position of which location is calculated as described in our co-pending International publication No. W097/09842 of even date herewith, to launch bending waves into the panel to cause the panel to resonate to radiate an acoustic output.
The transducer is driven by a signal amplifier e.g. an audio amplifier, connected to the transducer by conductors Amplifier loading and power requirements can be entirely normal, similar to conventional cone type speakers, sensitivity being of the order of 86 88dB/watt under room loaded conditions.
Amplifier load impedance is largely resistive at 6 ohms, power handling 20-80 watts. Where the panel core and/or skins are of metal, they may be made to act as a heat sink WO 97/09845 PCT/GB96/02158 6 for the transducer to remove heat from the motor coil of the transducer and thus improve power handling.
Figures 2a and 2b are partial typical cross-sections through the loudspeaker (81) of Figure 1. Figure 2a shows that the frame surround and panel are connected together by respective adhesive-bonded joints Suitable materials for the frame include lightweight framing, e.g. picture framing of extruded metal e.g.
aluminium alloy or plastics. Suitable surround materials include resilient materials such as foam rubber and foam plastics. Suitable adhesives for the joints (20) include epoxy, acrylic and cyano-acrylate etc. adhesives.
Figure 2b illustrates, to an enlarged scale, that the panel is a rigid lightweight panel having a core (22) e.g. of a rigid plastics foam (97) e.g. cross linked polyvinylchloride or a cellular matrix (98) i.e. a honeycomb matrix of metal foil, plastics or the like, with the cells extending transversely to the plane of the panel, and enclosed by opposed skins (21) e.g. of paper, card, plastics or metal foil or sheet. Where the skins are of plastics, they may be reinforced with fibres e.g. of carbon, glass, Kevlar (RTM) or the like in a manner known per se to increase their modulus.
Envisaged skin layer materials and reinforcements thus include carbon, glass, Kevlar (RTM), Nomex (RTM) i.e.
aramid etc. fibres in various lays and weaves, as well as paper, bonded paper laminates, melamine, and various synthetic plastics films of high modulus, such as Mylar WO 97/09845 PCT/GB96/02158 7 (RTM), Kaptan (RTM), polycarbonate, phenolic, polyester or related plastics, and fibre reinforced plastics, etc. and metal sheet or foil. Investigation of the Vectra grade of liquid crystal polymer thermoplastics shows that they may be useful for the injection moulding of ultra thin skins or shells of smaller size, say up to around 30cm diameter.
This material self forms an orientated crystal structure in the direction of injection, a preferred orientation for the good propagation of treble energy from the driving point to the panel perimeter.
Additional such moulding for this and other thermoplastics allows for the mould tooling to carry location and registration features such as grooves or rings for the accurate location of transducer parts e.g. the motor coil, and the magnet suspension. Additional with some weaker core materials it is calculated that it would be advantageous to increase the skin thickness locally e.g.
in an area or annulus up to 150% of the transducer diameter, to reinforce that area and beneficially couple vibration energy into the panel. High frequency response will be improved with the softer foam materials by this means.
Envisaged core layer materials include fabricated honeycombs or corrugations of aluminium alloy sheet or foil, or Kevlar (RTM), Nomex (RTM), plain or bonded papers, and various synthetic plastics films, as well as expanded or foamed plastics or pulp materials, even aerogel metals if of suitably low density. Some suitable core layer WO 97/09845 PCT/GB96/02158 8 materials effectively exhibit usable self-skinning in their manufacture and/or otherwise have enough inherent stiffness for use without lamination between skin layers. A high performance cellular core material is known under the trade name 'Rohacell' which may be suitable as a radiator panel and which is without skins. In practical terms, the aim is for an overall lightness and stiffness suited to a particular purpose, specifically including optimising contributions from core and skin layers and transitions between them.
Several of the preferred formulations for the panel employ metal and metal alloy skins, or alternatively a carbon fibre reinforcement. Both of these, and also designs with an alloy Aerogel or metal honeycomb core, will have substantial radio frequency screening properties which should be important in several EMC applications.
Conventional panel or cone type speakers have no inherent EMC screening capability.
In addition the preferred form of piezo and electro dynamic transducers have negligible electromagnetic radiation or stray magnet fields. Conventional speakers have a large magnetic field, up to 1 metre distant unless specific compensation counter measures are taken.
Where it is important to maintain the screening in an application, electrical connection can be made to the conductive parts of an appropriate DML panel or an electrically conductive foam or similar interface may be used for the edge mounting.
WO97/09845 PCT/GB96/02158 9 The suspension may damp the edges of the panel (2) to prevent excessive edge movement of the panel.
Additionally or alternatively, further damping may be applied, e.g. as patches, bonded to the panel in selected positions to damp excessive movement to distribute resonance equally over the panel. The patches may be of bitumen-based material, as commonly used in conventional loudspeaker enclosures or may be of a resilient or rigid polymeric sheet material. Some materials, notably paper and card, and some cores may be self-damping. Where desired, the damping may be increased in the construction of the panels by employing resiliently setting, rather than rigid setting adhesives.
Effective said selective damping includes specific application to the panel including its sheet material of means permanently associated therewith. Edges and corners can be particularly significant for dominant and less dispersed low frequency vibration modes of panels hereof.
Edge-wise fixing of damping means can usefully lead to a panel with its said sheet material fully framed, though their corners can often be relatively free, say for desired extension to lower frequency operation. Attachment can be by adhesive or self-adhesive materials. Other forms of useful damping, particularly in terms of more subtle effects and/or mid- and higher frequencies can be by way of suitable mass or masses affixed to the sheet material at predetermined effective medial localised positions of said area.
WO 97/09845 PCT/GB96/02158 An acoustic panel as described above is bidirectional. The sound energy from the back is not strongly phase related to that from the front.
Consequently there is the benefit of overall summation of acoustic power in the room, sound energy of uniform frequency distribution, reduced reflective and standing wave effects and with the advantage of superior reproduction of the natural space and ambience in the reproduced sound recordings.
While the radiation from the acoustic panel is largely non-directional, the percentage of phase related information increases off axis. For improved focus for the phantom stereo image, placement of the speakers, like pictures, at the usual standing person height, confers the benefit of a moderate off-axis placement for the normally seated listener optimising the stereo effect. Likewise the triangular left/right geometry with respect to the listener provides a further angular component. Good stereo is thus obtainable.
There is a further advantage for a group of listeners compared with conventional speaker reproduction. The intrinsically dispersed nature of acoustic panel sound radiation gives it a sound volume which does not obey the inverse square law for distance for an equivalent point source. Because the intensity fall-off with distance is much less than predicted by inverse square law then consequently for off-centre and poorly placed listeners the intensity field for the panel speaker promotes a superior stereo effect compared to conventional speakers. This is because the off-centre placed listener does not suffer the doubled problem due to proximity to the nearer speaker; firstly the excessive increase in loudness from the nearer speaker, and then the corresponding decrease in loudness from the further loudspeaker.
There is also the advantage of a flat, lightweight panel-form speaker, visually attractive, of good sound quality and requiring only one transducer and no crossover for a full range sound from each panel diaphragm.
Figure 3 illustrates a floor-mounted panel-form loudspeaker (81) of the kind generally shown in Figures 1 and 2 and in which a lightweight rigid rectangular distributed mode sound radiating panel is mounted on a resilient surround which in turn is supported in a rectangular frame The frame is supported by a floor stand (23) having a ground-engaging foot (83) supporting an upright stem (84) having four generally horizontal arms connected at their distal ends (86) to the respective corners (87) of the frame A balanced pair of transducers are mounted at one respective end on the panel and at their other ends are also supported on lugs (88) on the stem (84) to drive the panel.
The pair of transducers are located on the panel at predetermined locations as discussed below. This arrangement is intended to operate to drive the panel (2)
V
WO 97/09845 PCT/GB96/02158 12 pistonically at low frequencies by reacting against the stem (84) which along with the arms (85) acts as the chassis of a conventional loudspeaker drive unit and to vibrate the panel at higher frequencies to cause it to resonate to produce an acoustic output. Such an arrangement requires that the suspension is compliant, i.e. like the roll surround of a conventional pistonic loudspeaker cone driver.
INDUSTRIAL APPLICABILITY The panel-form loudspeaker of the invention is relatively simple to make, and its flatness makes it relatively easy to house. It has a wide angle of acoustic dispersion in comparison to conventional loudspeakers.

Claims (7)

  1. 2. A panel-form loudspeaker according to claim 1, characterised in that the frame has a portion surrounding the radiator
  2. 3. A panel-form loudspeaker according to claim 1 or claim 2, characterised in that the resilient suspension is of an elastomeric material.
  3. 4. A panel-form loudspeaker according to claim 2 or claim 3 when dependent on claim 2, characterised in that the Sframe comprises a floor stand (23) having a ground AMENDED SHEET M 14 engaging portion a substantially upright portion (84) extending from the ground engaging portion and a plurality of arms (85) extending from the upright portion, the distal ends of which arms connect to the frame portion (1) surrounding the radiator. A panel-form loudspeaker according to claim 4, characterised in that the radiator is rectangular, and in that the arms (85) extend near to the corners of the radiator.
  4. 6. A panel-form loudspeaker according to claim 4 or claim characterised in that the transducer is mounted on or adjacent to the upright portion (84) of the frame.
  5. 7. A panel-form loudspeaker according to any one of claims 4 to 7, characterised in that the transducer is mounted on a lug (88) projecting from the upright portion.
  6. 8. A panel-form loudspeaker according to any preceding claim, characterised by a balancing pair of transducers
  7. 9. A panel-form loudspeaker according to any preceding claim, characterised in that the radiator comprises a lightweight core (22) separating a pair of high modulus lightweight skins (21). A panel-form loudspeaker substantially as herein described and as shown in any one of the embodiments of the accompanying drawings. DATED this Seventeenth Day of February 1998 New Transducers Limited Patent Attorneys for the Applicant SPRUSON FERGUSON [N:\Iibk]OO773:SFD
AU68814/96A 1995-09-02 1996-09-02 Loudspeakers comprising panel-form acoustic radiating elements Ceased AU703296B2 (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
GB9517918 1995-09-02
GBGB9517918.0A GB9517918D0 (en) 1995-09-02 1995-09-02 Acoustic device
GBGB9522281.6A GB9522281D0 (en) 1995-10-31 1995-10-31 Acoustic device
GB9522281 1995-10-31
GBGB9606836.6A GB9606836D0 (en) 1996-03-30 1996-03-30 Acoustic device
GB9606836 1996-03-30
PCT/GB1996/002158 WO1997009845A2 (en) 1995-09-02 1996-09-02 Loudspeakers comprising panel-form acoustic radiating elements

Publications (2)

Publication Number Publication Date
AU6881496A AU6881496A (en) 1997-03-27
AU703296B2 true AU703296B2 (en) 1999-03-25

Family

ID=34865245

Family Applications (1)

Application Number Title Priority Date Filing Date
AU68814/96A Ceased AU703296B2 (en) 1995-09-02 1996-09-02 Loudspeakers comprising panel-form acoustic radiating elements

Country Status (20)

Country Link
EP (1) EP0847664B1 (en)
JP (1) JPH11512255A (en)
CN (1) CN1194085A (en)
AT (1) ATE179563T1 (en)
AU (1) AU703296B2 (en)
BR (1) BR9610466A (en)
CA (1) CA2230161A1 (en)
CZ (1) CZ58298A3 (en)
DE (1) DE69602279T2 (en)
DK (1) DK0847664T3 (en)
EA (1) EA199800246A1 (en)
ES (1) ES2131957T3 (en)
HU (1) HUP9900168A3 (en)
IL (1) IL123487A (en)
NZ (1) NZ316556A (en)
PL (1) PL325211A1 (en)
RO (1) RO119044B1 (en)
SK (1) SK26398A3 (en)
TR (1) TR199800361T1 (en)
WO (1) WO1997009845A2 (en)

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GB9806994D0 (en) * 1998-04-02 1998-06-03 New Transducers Ltd Acoustic device
AU756783B2 (en) 1998-06-22 2003-01-23 Slab Technology Limited Loudspeakers
DE29811727U1 (en) 1998-07-01 1998-08-27 Alusuisse KAPA GmbH, 49090 Osnabrück Record speaker device
AU2002249373A1 (en) * 2001-04-05 2002-10-21 New Transducers Limited Loudspeaker
US6813362B2 (en) 2001-04-05 2004-11-02 New Transducers Limited Loudspeaker and method of making same
US11431312B2 (en) 2004-08-10 2022-08-30 Bongiovi Acoustics Llc System and method for digital signal processing
US10158337B2 (en) 2004-08-10 2018-12-18 Bongiovi Acoustics Llc System and method for digital signal processing
US8284955B2 (en) 2006-02-07 2012-10-09 Bongiovi Acoustics Llc System and method for digital signal processing
US10848118B2 (en) 2004-08-10 2020-11-24 Bongiovi Acoustics Llc System and method for digital signal processing
US10069471B2 (en) 2006-02-07 2018-09-04 Bongiovi Acoustics Llc System and method for digital signal processing
US9615189B2 (en) 2014-08-08 2017-04-04 Bongiovi Acoustics Llc Artificial ear apparatus and associated methods for generating a head related audio transfer function
US11202161B2 (en) 2006-02-07 2021-12-14 Bongiovi Acoustics Llc System, method, and apparatus for generating and digitally processing a head related audio transfer function
US10701505B2 (en) 2006-02-07 2020-06-30 Bongiovi Acoustics Llc. System, method, and apparatus for generating and digitally processing a head related audio transfer function
US10848867B2 (en) 2006-02-07 2020-11-24 Bongiovi Acoustics Llc System and method for digital signal processing
US9883318B2 (en) 2013-06-12 2018-01-30 Bongiovi Acoustics Llc System and method for stereo field enhancement in two-channel audio systems
US9264004B2 (en) 2013-06-12 2016-02-16 Bongiovi Acoustics Llc System and method for narrow bandwidth digital signal processing
US9906858B2 (en) 2013-10-22 2018-02-27 Bongiovi Acoustics Llc System and method for digital signal processing
US9615813B2 (en) 2014-04-16 2017-04-11 Bongiovi Acoustics Llc. Device for wide-band auscultation
US10820883B2 (en) 2014-04-16 2020-11-03 Bongiovi Acoustics Llc Noise reduction assembly for auscultation of a body
US10639000B2 (en) 2014-04-16 2020-05-05 Bongiovi Acoustics Llc Device for wide-band auscultation
US9564146B2 (en) 2014-08-01 2017-02-07 Bongiovi Acoustics Llc System and method for digital signal processing in deep diving environment
US9638672B2 (en) 2015-03-06 2017-05-02 Bongiovi Acoustics Llc System and method for acquiring acoustic information from a resonating body
US9621994B1 (en) 2015-11-16 2017-04-11 Bongiovi Acoustics Llc Surface acoustic transducer
US9906867B2 (en) 2015-11-16 2018-02-27 Bongiovi Acoustics Llc Surface acoustic transducer
CN112236812A (en) 2018-04-11 2021-01-15 邦吉欧维声学有限公司 Audio Enhanced Hearing Protection System
US10959035B2 (en) 2018-08-02 2021-03-23 Bongiovi Acoustics Llc System, method, and apparatus for generating and digitally processing a head related audio transfer function
US10782731B1 (en) * 2019-02-28 2020-09-22 Google Llc Modal frequency shifting for loudspeaker devices

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Also Published As

Publication number Publication date
CA2230161A1 (en) 1997-03-13
EA199800246A1 (en) 1998-10-29
HUP9900168A2 (en) 1999-04-28
ES2131957T3 (en) 1999-08-01
ATE179563T1 (en) 1999-05-15
IL123487A0 (en) 1998-09-24
IL123487A (en) 2001-11-25
JPH11512255A (en) 1999-10-19
WO1997009845A3 (en) 1997-05-29
AU6881496A (en) 1997-03-27
EP0847664A2 (en) 1998-06-17
RO119044B1 (en) 2004-02-27
CZ58298A3 (en) 1998-07-15
EP0847664B1 (en) 1999-04-28
SK26398A3 (en) 1998-09-09
HK1008644A1 (en) 1999-05-14
BR9610466A (en) 1999-03-02
CN1194085A (en) 1998-09-23
DK0847664T3 (en) 1999-11-08
DE69602279T2 (en) 1999-09-16
HUP9900168A3 (en) 2001-08-28
TR199800361T1 (en) 1998-05-21
WO1997009845A2 (en) 1997-03-13
DE69602279D1 (en) 1999-06-02
PL325211A1 (en) 1998-07-06
NZ316556A (en) 1998-05-27

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