Patent Publication Number: US-2010128905-A1

Title: Personal listening device

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This patent is a division of application Ser. No. 11/755,408, entitled “Personal Listening Device” filed May 30, 2007, which claims benefit under 35 U.S.C. §119 (e) to U.S. Provisional Application No. 60/803,487, filed May 30, 2006 and entitled “Assistive Listening System,” the disclosures both of which are hereby incorporated by reference herein in their entireties for all purposes. 
    
    
     BACKGROUND 
     Various hearing aids and earpiece devices are known in the art. Many take the form of a Behind-the-Ear (BTE), In-The-Ear (ITE), In-the-Canal (ITC), Completely-In-The Canal (CIC), or Receiver-in-the-Ear (RIE) component. In a typical hearing aid, the hearing aid is constructed with a four-piece structure, e.g. internal components for the receiver, receiver housing, surrounding structure, and an ear mold or compliant ear dome/tip. The receiver comprises a housing that is made of metal or a non-biocompatible material. Some wearers may be allergic to metal housing, and the wearer may experience discomfort when the receiver housing is directly in the ear canal. 
     The tissues covering the bony region of the ear are relatively thin and, therefore, little or no tolerance for expansion exists in this region as compared to the tissues covering the cartilaginous region. Inserting the metal receiver deeply into the ear canal so that it touches the bony region not only damages the tissues in the bony region, but the wearer will experience great pain. 
     The ear mold or compliant ear dome/tip is attached to the surrounding structure and then inserted into the ear canal for comfort wear. The ear mold and the surrounding structure must be carefully removed in order to reach the receiver, and once the receiver has been repaired or replaced, the receiver is inserted back into the ear mold and the surrounding structure. 
     The surrounding structure has been used to accomplish several tasks: protect the user from non-biocompatible receiver housing, provide ease of assembling the ear fit device, and protect the electrical and mechanical portions of the device from ear wax, perspiration, and various environmental contaminants. 
     A disadvantage in using the four-piece structure, e.g. internal components for the receiver, receiver housing, surrounding structure, and ear mold, for the earphone or the hearing aid is that it is very bulky by nature. Also, it is very difficult to design and control the design parameters of the surrounding structure to suit different receiver and hearing aid configurations. It is not suited for low cost mass production. In addition, in some cases, the structure needs to be taken apart in order to repair and or replace the receiver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawings wherein: 
         FIG. 1  is a block diagram showing the communication link between a personal listening device and an external device according to various embodiments of the present invention; 
         FIG. 2  is a perspective view of a personal listening device that may be utilized in various types of devices according to various embodiments of the present invention; 
         FIG. 3  is a detailed block diagram showing an interface between a personal listening device and an external device in accordance with various embodiments of the present invention; 
         FIG. 4  is a simplified block diagram of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 5  is a simplified block diagram of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 6  is a simplified block diagram of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIGS. 7A-7C  are different views of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 8  is a cross-sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIGS. 9A-9C  are different views of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIGS. 10A-10C  are different views of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIGS. 11A-11C  are different views of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 12  is a cross-sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIGS. 13A-13B  is a cross-sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 14  is a sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention; 
         FIG. 15  is a sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention; and 
         FIG. 16  is a cross-sectional view of another exemplary personal listening device in accordance with various embodiments of the present invention. 
     
    
    
     Skilled artisans will appreciate that all elements in the figures are illustrated for simplicity and clarity. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence which those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. 
     DETAILED DESCRIPTION 
     While the present disclosure is susceptible to various modifications and alternative forms, certain embodiments are shown by way of example in the drawings and, these embodiments will be described in detail herein. It will be understood, however, that this disclosure is not intended to limit the invention to the particular forms described, but to the contrary, the invention is intended to cover all modifications, alternatives, and equivalents falling within the spirit and scope of the invention defined by the appended claims. 
       FIGS. 1-2  illustrate the flexibility and usefulness of a personal listening device  2  to be fitted in the ear, on the ear, near the ear, or behind the ear, in accordance with one or more of the herein described embodiments. The personal listening device  2 , which may be virtually any personal listening device or system such as a hearing aid  8 , an earphone  10 , a headphone (not shown), a wireless headset  12 , an insert earphone (not shown), and the like. Other examples of devices are possible. An optional communication link  4 , which can be a direct wired link or a wireless link, couples the personal listening device  2  to an external device  6 . The external device  6  may be virtually any electronic device, a gaming device and the like such as a computer (e.g. a desktop, a laptop  14 , a notebook, a tablet  22 , a hand-held computer, a Personal Digital Assistant (PDA)  16 , etc), a communication device (e.g. cellular telephone  20 , a web-enabled cellular telephone, a cordless telephone, a pager, etc), a computer-related peripheral (e.g. a printer, a scanner, a monitor, etc), an entertainment device (e.g. a television, a radio, a stereo, a tape and/or compact disc player, a digital layer 3 (MP3) player, etc), a digital camera  18  and the like. Other examples of devices are possible. The external device  6  needs only to be capable of or configured to be capable of communication over one or more public or private communication networks. 
     The communication link  4  transmits and receives data or signals over the air (in a wireless mode) or over the wire (in a wired mode). 
       FIG. 3  illustrates a detailed block diagram of a personal listening device  2 . The personal listening device  2  comprises a first module  30 , a second module  40 , and a communication link  50  adapted to couple or decouple the first and second modules  30 ,  40 . In this example, the first and second modules  30 ,  40  may be a Receiver-in-the-Ear (RIE), a Behind-the-Ear (BTE), In-the-Ear (ITE), In-the-Canal (ITC), Completely-in-the-Canal (CIC) component or combination thereof. Other examples of devices are possible. Alternatively the modules  30 ,  40  may be integrated to form a single device. More aspects about the formation of the system  2  are described elsewhere in this specification. At least a portion of the personal listening device  2  may be optionally coupled to an external device  6  via a second communication link  4  adapted to couple or decouple the personal listening device  2  and the external device  6 . The first and second communication links  50 ,  4  may be virtually any communication link, and for example, the communication links  50 ,  4  may be constructed and defined or configured to operate in a wired mode, a wireless mode, or both wired and wireless modes to transmit and receive data or signals over the air or over the cable. If the system  2  and the external device  6  are constructed in a wireless mode to radiate signals in the radio frequency (RF) range for instance, the system  2  may be at a remote location with respect to the external device  6 . Alternatively, the system  2  and the external device  6  may be converted to a wired mode by means of plugging the wired link  50  and/or  4 . 
     The module  30  may include one or more devices, e.g.  32  or  34 , to deliver an acoustic energy directly to the ear canal. The devices  32 ,  34  may be a receiver, a dual receiver, a microphone/receiver, or a microphone with a dual receiver, depending on the desired applications. Other types of electroacoustic transducers are possible. In this example, the receiver may be a silicon (micro-electromechanical machined, MEMS) receiver, a balanced armature receiver, a bone-conduction receiver, or combinations thereof for the conversion of an electrical audio frequency signal to an acoustic or vibratory signal, depending on the desired applications. Alternatively, the devices  32 ,  34  may be selected to have virtually any frequency response. For example, the devices  32 ,  34  may be low-range frequency (LF) receivers, mid-range frequency (MF) receivers, high-range frequency (HF) receivers, or a combination thereof. The microphone may be a silicon (MEMS) condenser microphone, an electret microphone, an omni-directional microphone, a directional microphone, a dynamic microphone, or a monitor microphone such as the monitor microphone disclosed in U.S. patent Ser. No. 11/382,318, filed on May 9, 2006, the disclosure of which is herein incorporated by reference in its entirely for all purpose, depending on the desired applications. Other types of microphones are possible. The module  30  may further include other electronic components such as a power source  36 , a transceiver  38  with an antenna  39 , and a processor (not shown). The transceiver  38  is configured to send and receive signals between the modules  30 ,  40  via the wireless communication link  50 . The power source  36  is coupled to the rest of the electronic components to provide power. The processor (not shown) may be a signal processing unit, a speech processing unit, a multi-function processing unit or the like, and it is coupled between the transducers  32 ,  34  and the transceiver  38 . Other types of processor are possible. The antenna  39  is used to transmit and receive signals from the transceiver  38 . The antenna  39  may be external or internal to the module  30 . The antenna  39  may serve as part of the communication link. Alternatively, the antenna  39  may serve as part of the retrieval member to remove the module  30  from the ear. 
     The module  40  includes at least one device  42 . The device  42  may be a microphone to receive sound from the outside environment. Alternatively, the device  42  may be multiple devices such as a microphone/receiver, a dual microphone, or a plurality of microphones. The module  40  may further include other electronic components such as a power source  44 , a signal processing unit  46 , and a transceiver  48  with an antenna  49 . The microphone  42  converts acoustic signals into electrical signals and transfers such electrical signals to the signal processing unit  46  for processing before such signals are transmitted to the module  30  via the optional transceiver  48 . Like the transceiver  38  of module  30 , the transceiver  48  is in operative communication with the transducer  42  and/or the external device  6  and is configured to transmit and receive wireless communication in accordance with any suitable protocol such as Bluetooth, Ultra-Wideband (UWB), Home Radio Frequency (HomeRF), Digital Enhanced Cordless Telephone (DECT), Personal Handy System (PHS), wireless LAN (WLAN), or other open or proprietary protocols now known or later developed that are capable to couple between the modules  30 ,  40  and/or the external device  6 . The antenna  49  is used to transmit and receive signals from the transceiver  48 . The antenna  49  may be external or internal to the module  40 . The power source  44  is coupled to the rest of the components of the module  40  to provide power. Other circuitry such as a speech processing unit, switching means, digital audio compression and depression, oscillator-FM modulator, multipliers, expender, FM detector, down-converter and intermediate frequency (IF), or the like now known or later developed may be provided in the modules  30 ,  40  to perform certain operations. 
     The external device  6 , such as a mobile phone, has the capability to send and receive a wide variety of audio signals between the system  2  either by the wired link or a wireless link  4 ,  24  and a wireless network  26 . In turn, it is connected to the public switched telephone network (PSTN). The wireless network  26  may be a cellular network, a paging network, or the like. Other types of network are possible. The cellular network  26  includes common data service network protocols for sending and receiving information to and from the mobile phone such as AMPS (analog signal), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Personal Handy System (PHS), Digital Enhanced Cordless Telephony (DECT), General Packet Radio Service (GPRS), or other open or proprietary wireless data service protocols now known or later developed. Alternatively, the external device  6  may be other types of electronic devices (See  FIG. 2 ) that do not require communication with a wireless network. 
       FIG. 4  illustrates a simplified block diagram of a personal listening device  2 . In this example, module  30  is electrically coupled to a second module  40  via a wired communication link  50 . The module  30 , which is capable of converting amplified signals to acoustic signals before transmitting to the ear canal of a user, comprises an acoustic assembly and a motor assembly that is attached to the acoustic assembly via a coupling assembly. The assemblies are disposed within a housing  28 . The housing  28  may be made of any biocompatible material and has no adverse effect on the surrounding tissue. More aspects about the formation of the module  30  will be discussed in greater detail herein. In this example, the module  30  may be a RIE, CIC, ITC, ITE, or any body-worn device. Other types of listening devices are possible. The module  40  comprises a microphone  42  and a signal processing unit  46  disposed in a housing  54 . Alternatively, the microphone  42  may be separated from the signal processing unit  46  and is located outside the housing  54 . A second communication link (not shown) couples the microphone  42  to the module  40  and/or the module  30 . A microphone  42  comprises a housing (not shown) made of any bio-compatible material that is used to encapsulate the internal components and is then inserted into the auditory canal. The module  40  may be a BTE, ITE, or ITC. Other types of listening devices are possible. More than one microphone may be provided. The microphone  42  receives acoustic signals from the external environment and converts such signals into electrical signals before the signals are transmitted to the signal processor unit  46 . The signal processor unit  46  then amplifies the signal received from the microphone  42  and delivers the processed signal to the module  30  via the communication link  50 . More aspects about the formation of the communication link  50  are described elsewhere in this specification. 
       FIG. 5  illustrates a simplified block diagram of a personal listening device  2 . In this example, the first and second modules  30 ,  40  are integrated into a single unit. The module  30  capable of converting amplified signals to acoustic signals before transmitting to the ear canal of a user comprises an acoustic assembly and a motor assembly that is attached to the acoustic assembly via a coupling assembly. The assemblies are disposed within a housing  28 . The housing  28  may be made of any biocompatible and has no adverse effects on the surrounding tissue in the ear canal. The module  40  comprises a microphone  42  and a signal processing unit  46 . More than one microphone may be included. The microphone  42  and the signal processing unit  46  are disposed in a housing  54 . The housing  28  comprises a connecting member  52  configured to attach the plastic body  28  to the housing  54 . Alternatively, the housing  28  of the module  30  has a first end adapted to couple and decouple with the housing  54  of the module  40  by mechanical fastening, crimping, welding, adhesive bonding, or any other suitable attachment arrangement now known or later developed. The module  30  or  40  is easily removed and replaced if the module  30  or  40  fails for any reason. In this example, the system  2  may be a CIC, ITC, ITE, BTE, or RIE component. 
       FIG. 6  illustrates a simplified block diagram of a personal listening device  2 . In this example, a module  30  is a listening device. The listening device  30  may be an earphone, an earplug, a headphone, a wireless earphone, a wireless headset, a wireless headphone, an insert earphone and the like. Other types of devices are possible. The listening device  30  comprises at least one earphone to be positioned in an ear canal. The earphone  30  may be electrically coupled to an electronic device  6  via a suitable communication link  50  that provides audio signals to the earphone  30 . Alternatively, a user input device (not shown) may be coupled to the earphone  30  to perform different functions. The earphone  30  comprises a plastic body  28  to be worn by a user. An acoustic assembly and a motor assembly coupled to the acoustic assembly via the coupling assembly are collectively disposed within the housing  28 . An outer surface of the body  28  can take various forms or shapes adapted for fitting to the user&#39;s ear. Alternatively, an ear impression, a sealed mold, an ear tip, an ear mold, an ear dome, an ear tube, an ear mold, an ear bud, an ear cone, or an ear plug of varying sizes and shapes, or the like may be used to cover at least a portion of the body  28 . This allows the user to wear the listening device  30  comfortably for an extended period of time. The body  28  with or without the ear tip provides a good seal in the ear. Alternatively, the body  28  may be smaller in size than the interior of the auditory canal whereby the body  28 , with or without the ear tip, does not occlude the ear canal. 
     In this example, the external device  6  may be a communication device, an audio device, a gaming device, an entertainment device, or combination thereof. Other types of devices are possible. 
       FIGS. 7A-7C  illustrate different views of a personal listening device  2 . In this example, the system  2  is configured to generate acoustic energy in the ear canal of the wearer. The system  2  can function on either ear. In this example, the system  2  is a receiver to drive an acoustic signal directly to the ear canal. The system  2  comprises a housing  28 , a connector assembly  52 , and a tube assembly  62 . The housing  28  comprises a top housing  28   a  and a bottom housing  28   b . Although the top housing  28   a  and the bottom housing  28   b  are depicted, it is possible to add additional structures. For example, a spacer may be added between the top housing  28   a  and the bottom housing  28   b  to increase the overall height and volume of the housing  28  or the bottom housing  28   b  and the top housing  28   a  may be molded as a single structure. A chamber  64  is formed within the housing  28  to receive a motor assembly  68 . The chamber  64  may generally be shaped to correspond to the shape and configuration of the assemblies  66 ,  68  but may be formed to compliment the various shape of the different examples, including a roughly square shape, a cylindrical shape or other desired geometry. As shown, the chamber  64  has a rectangular in cross-sectional shape. In addition, the scale and size of the chamber  64  may vary based on the intended applications, operating conditions, required components, etc. The outer surface of the housing  28  can take various forms or configurations adapted for fitting to the user&#39;s ear. The housing  28  may be shaped to fit into the external auditory canal without blocking the canal. Alternatively, the housing  28  may be designed to comfortably fit in the user&#39;s ear and yet provides a good seal. The housing  28  may be manufactured from any type of moldable or formable material that is corrosion resistant and bio-compatible for skin contact, including plastic, polycarbonate, nylon, liquid crystal polymer (LCP), PEEK, or any other similar materials. Alternatively, part of the housing  28  may be made of magnetically soft steel, such as metal injection molded material, that is capable of providing electromagnetic shielding or to function as part of the magnetic return path for the motor assembly  68 . Such material may be provided to the inner wall of the housing  28 , between layers of the bio-compatible, corrosion-resistant material, or outer wall of the housing  28 . Yet in another example, the housing  28  may be made of any material, including, but is not limited to Acetal Copolymer or Homopolymer (POM) (Delrin), Acrylic (PMMA), Acrylonitrile Butadiene Styrene (ABS), Cellulose Acetate (CA, CB, CP), Polyamide (Nylons), Polyimide (Kapton), Polycarbonate (PC) (Lexan), Polyethylene Terephthalate (PET), Polyetherimide (PEI) (Ultem), Polyetheretherketone (PEEK), Polyethylene, Polyphenylene Oxide (PPO) (Noryl), Polyphenylene Sulphide (PPS), Polypropylene (PP), Polystyrene, Polyvinyl Chloride (PVC), Styrene Acrylonitrile (SAN/ASA), Polyphtalamide (PPA), Polysulphone, polyphenylsulfone (Radel), polybutylene terephthalate (PBT) (Pocan), Polyphthalamide (PPA), Fluoropolymers, Polyarylate, Silicone, or the like. Material may be a blend or alloy of these materials. The material may or may not include additives for providing strength and expansion control such as glass content, carbon fiber, or the like. Other materials for providing one or more features, including electrical conductivity, magnetic conductivity, UV stabilization, moisture absorption, moldability, chemical resistance, temperature resistance, flexibility, durability, and hardness, may or may not be added to the base material as disclosed above. Other types of materials are possible. An optional non-biocompatible thin film or layer (not shown) may be provided to the housing  28  such that at least a surface of the housing is covered by the film or layer. Alternatively, the housing  28  comprises alternating layers of material, at least one layer of biocompatible material and at least one layer of non-biocompatible material. In another example, the housing  28  comprises an innermost layer that is made of biocompatible material, and at least a portion of the inner surface is provided with a non-biocompatible thin film or layer. The thin film may be made of any material that enhances electromagnetic performance, adhesive characteristics, corrosion characteristics, and environmental protection such as copper, gold, epoxy, primers, or sealant. Alternatively, other types of thin film used for surface treatments in order to enhance adhesion of parts, sealants to encapsulated and protect parts, paints, treatments, thin films for decorative or other reasons may be used. Unlike previous listening devices, the overall size of the module  2  is reduced and a second housing, also known as a surrounding structure is no longer required. 
     The motor assembly  68  comprises a drive magnet (not shown), a magnetic yoke  70 , a coil  72  with or without a bobbin, an armature  74 , and a coupling assembly  76 . The device  2  further comprises an acoustic assembly  66 . The acoustic assembly  66  may be a single layer diaphragm assembly, a multiple layer diaphragm assembly, or the like. The acoustic assembly  66  may be manufactured in a variety of shapes and sizes that may or may not correspond to the chamber  64  and/or the motor assembly  68 . For example, the acoustic assembly  66  may be wider and longer or may be narrower and shorter than the motor assembly  68 . More aspects about the configuration of the acoustic assembly  66  are described elsewhere in this specification. The acoustic assembly  66  divides the chamber  64  into a back volume  100  and a front volume  102 . 
     The coupling assembly  76  may be a drive rod, a linkage assembly, a plurality of linkage assemblies, or the like. The drive magnet (not shown) may be made of a hard magnetic material such as Ferrite, AlNiCo, Samarium-Cobalt, Neodymium-Iron-Boron, or of any other similar materials. Other types of materials are possible. It will be understood that virtually any magnet shape or configuration suitable for the desired application may suffice. The magnetic yoke  70  may be made of a permeable, soft magnetic material, including Nickel-Iron, Nickel-Iron-Molybdenum, steels, cobalt-iron-vanadium, or any similar alloys and materials. Other types of materials are possible. The magnetic yoke  70  may be formed to compliment the various shape and size of the different examples. As shown, the magnet is fixedly attached to the inner wall of the magnetic yoke  70 . Although the magnet and the magnetic yoke are a two-piece structure, it is possible to construct the magnet and the yoke  70  as a single unit. The armature  74  is generally U-shaped. One of ordinary skill in the art will appreciate that the armature  74  may be E-shaped, Y-shaped, or of a different configuration and size suitable for the desired application. The coil  72  is made of electrically conductive materials having thickness and a plurality of turns. In alternate examples, the coil may be made of alternating layers of insulating and conducting materials. Other types of materials are possible. As shown in  FIG. 7B , the coil  72  is sized to conform to the shape of the chamber  64 , but may be produced in a variety of shapes and sizes that may or may not correspond to the chamber  64 . For example, the coil  72  may be an oval shape having a dimension smaller than the chamber  64  while the chamber  64  may be manufactured having a rectangular shape. An optional acoustic structure and/or an electrical structure are disposed in the housing  28 . The structures may be acoustic compliances, acoustic resistances, acoustic inertances, damping, acoustical filters, chambers, tubes, ports, vents, electrical filters, or combinations thereof. 
     In this example, the armature  74  comprises a movable leg extending through the coil  72  and the magnetic yoke  70  and a fixed leg secured outside the magnetic yoke  70  by any known technique. One end of the coupling assembly  76  is attached to a free end of the movable armature  74  by any known technique and the opposite end of the coupling assembly  76  is attached to the acoustic assembly  66  by any known technique. Alternatively, the diaphragm  66  may be coupled directly to the movable leg of the armature  74 . Two wires  76  extend from the coil  72  and are electrically coupled to pins  78  which protrude through a rear wall  80  of the chamber  64 . Alternatively, the wires  76  are electrically coupled to a communication link (not shown). Locking members  104  formed on the bottom housing  28   b  secure the pins  78  in proper position and a strain relief  52  for protecting the wires  76  and the pins  78  secures and retains the communication link. The wires  76  receive an electrical input signal that is converted by the acoustic assembly  66  and the motor assembly  68  to an acoustic signal which is broadcast through an outlet  84 . As shown in  FIGS. 7B-7C , the outlet  84  is provided on the top housing  28   a  by any known technique and is directly connected to the back volume  100  to allow acoustic energy to be transmitted to the user. Although one outlet  84  is depicted, it is possible to provide an additional outlet or acoustic path. The communication link  50  may be made of similar material to the housing  28 . Use of other types of materials that posses sufficient structural properties and rigidity is possible. The housing  28  has a first end  82  adapted for mechanical connection with a first end  106  of the connector assembly  52 . If the connector assembly fails for any reason, the connector assembly is easily removed and replaced with a functional connector assembly  52 . The strain relief  52  may be posed of sufficient structural properties and yet rigidity for insertion and removal of the system  2  from the auditory canal without separating the strain relief  52  from the housing  28 . Once the acoustic assembly  66  and the motor assembly  68  are held in place in the chamber  64 , the top and bottom housing  33   a ,  33   b  are then fixedly attached together by any known technique. 
     As shown, the tube assembly or the channel  62  has an opening  98  adapted for accommodation of the wax screen  96  that is positioned in the transmission path of sound that is emitted from the outlet  84  by the assemblies  66 ,  68 . The wax screen  96  is used to protect the internal components from damage. Like the connector assembly  52 , the tube portion  62  may be made of similar material as the housing  28 . Use of other types of material is possible. The tube portion  62  is coupled to a second end  108  of the housing  28  by any known technique. The tube assembly  62  may be manufactured in a variety of lengths and dimensions to modify the frequency response of the module  30 . In certain applications, the tube assembly  62  is not required and the acoustic assembly  66  via the outlet  84  is exposed to the ear canal for direct transmission of sound into the user&#39;s ear. An optional wax screen may be provided to cover the outlet  84  against cerumen or ear wax. Alternatively, at least one aperture may be formed on the housing  28  to provide a flow path for cleaning liquids that are used when flushing out the front volume  102  and cleaning the acoustic assembly  66 . Wax protection measures such as removable or cleanable wax grids, wax plungers, or the like may be inserted in the acoustic path between the acoustic assembly  66  and the ear canal. Alternatively, a portion of the housing  28  may be removed to clean, service, or rework the internal components. 
       FIG. 8  illustrates a cross-sectional view of a personal listening device  2 .  FIG. 8  is similar in construction to the system  2  in  FIG. 7C . As mentioned earlier, a strain relief member  79  may be formed as part of a communication link  50  is provided at the rear wall  80  of the housing  28 . The strain relief member  79  is provided for retaining the wire  76  and to prevent accidental removal of the communication link  50  from the motor assembly  68 . The communication link  50  preferably is stretchable, bendable and preferably retains the conductor  86  in position. As shown, the conductor  86  may be wound as a helix to prevent breaking when the cable is stretched. An optional retrieval member may be provided to the system  2  for removal of the system  2  from the ear canal. The retrieval member may be formed as part of the communication link  50 . A portion of the communication link  50  extending from the housing  28  may be hollow, providing acoustical measures to modify the frequency response of the system  2 . 
       FIGS. 9A-9C  illustrate different views of a personal listening device  2 .  FIGS. 9A-9C  are similar in construction to the system  2  of  FIGS. 7A-7C  except that a short tube  84  serving as an acoustic outlet protrudes from a second end  108  of the housing  28 . The short tube  84  is coupled to the inner wall of a tube assembly  62 , and a wax screen  96  is attached in the tube assembly  62  opposed to the outlet  84  by any suitable method of attachment. An optional dampening or an acoustic labyrinth may be provided within the tube assembly for tuning an acoustic response. Alternatively, the wax screen  96  may be coupled directly to the outlet  84  if the tube assembly  62  is not provided. A connector assembly  52  comprises a plurality of flange  94  adapted for coupling or decoupling the housing  28 , is mounted to the outer wall of the housing  28  such that a portion of the housing  28  is covered by the connector assembly  52 . 
       FIGS. 10A-10C  illustrate different views of a personal listening device  2 .  FIGS. 10A-10C  are similar in construction to the system  2  of  FIGS. 9A-9C . In contrast to the system  2  in the foregoing figures, a tube assembly  62  adapted to couple or decouple is provided to the front wall of a housing  28 . A second chamber  60  is provided to fixedly attach the wire  88  to the second chamber  60  by any known technique. A first end of a communication link  50  is electrically coupled to the wire  88  and a second end (not shown) of the communication link  50  is connected to the external device (not shown). 
       FIGS. 11A-11C  illustrate different views of a personal listening device  2 . In contrast to the system  2  in the foregoing figures, the system  2  comprises two acoustic assemblies  66   a ,  66   b  and two motor assemblies  68   a ,  68   b , collectively disposed in a housing  28 . As shown, the acoustic assemblies  66   a ,  66   b  are arranged such that the assemblies  66   a ,  66   b  face each other and share a common front volume  102 . A first back volume  100   a  and a second back volume  100   b  are formed in the chamber  64 , wherein the first motor assembly  68   a  is disposed in the first back volume  100   a  and the second motor assembly  68   b  is disposed in the second back volume  100   b . Alternatively, the motor assemblies  68   a ,  68   b  may share a common back volume  100  and the acoustic assemblies  66   a ,  66   b  separate the chamber  64  to form first and second back volumes  102   a ,  102   b . An optional structure (not shown) may be provided to separate the assemblies  66   a ,  66   b ,  68   a ,  68   b  such that two chambers  64   a ,  64   b  are formed. The assemblies  66   a ,  66   b ,  68   a ,  88   b  no longer share a common volume. The assemblies  66   a ,  68   a  are disposed in the first chamber  64   a  and the assemblies  66   b ,  68   b  are disposed in the second chamber  64   b.    
       FIG. 12  illustrates a cross-sectional view of an assistive system  2 . In contrast to the system  2  in  FIG. 11 , the system  2  comprises two motor assemblies  68   a ,  68   b  and an acoustic assembly  66 . The ends of the acoustic assembly  66  may be hinged to the side walls of the housing  28 , the inner walls of the housing  28 , or other support members provided within the housing  28 . The motor assemblies  68   a ,  68   b  are coupled to the acoustic assembly  66  by any known technique. In this example, the coupling assembly  76   a  is positioned at one end of the acoustic assembly  66  (close to the front wall of the housing  28 ), and the coupling assembly  76   b  is positioned at the opposite end of the acoustic assembly  66  (close to the rear wall of the housing  28 ). The motor assemblies  68   a ,  68   b  share a common back volume  100 , and the diaphragm assembly  66  vibrates in response to the assemblies  68   a ,  68   b . At least one sound port may be provided to directly connect the front volume  102  to allow acoustic energy to be transmitted to the user. In this example shown, two ports  84   a ,  84   b  are provided to roll off occlusion effect and low frequency. Alternatively, a second sound port may be provided in communication with the back volume  100  for pressure equalization between the back volume  100  and the surrounding. 
       FIGS. 13A-13B  illustrate cross-sectional views of an assistive system  2 . Unlike from  FIG. 12 , the coupling assembly  76   b  is positioned in the mid portion of the acoustic assembly  66  within the chamber  64 . In this configuration, the coupling assemblies  76   a ,  76   b  provide further support to the acoustic assembly  66  when the acoustic assembly  66  is excited by the motor assemblies  68   a ,  68   b . Alternatively, an optional structure is provided to separate the motor assemblies  68   a ,  68   b  so that the assemblies  68   a ,  68   b  no longer share a common back volume  100 . Two front volumes  100   a ,  100   b  are illustrated in  FIG. 13B , wherein the motor assembly  68   a  corresponds to the first back volume  100   a  and the motor assembly  68   b  corresponds to the second back volume  100   b . A common front volume  102  is formed and shared by the first and second acoustic assemblies  66   a ,  66   b.    
       FIG. 14  illustrates a sectional view of an assistive system  2 . The system  2  comprises a first module  30 , a second module  40 , and communication links  50   a ,  50   b  between the modules  30 ,  40 . The first module  30  includes a high frequency (HF) transducer. Also, an optional ear mold  118  may be provided such that a portion of the module  30  is disposed in the ear mold  118 . A sound outlet tube  62   a  coupled to the HF transducer  30  is mated with a first sound port  84   a  formed within the ear mold  118 . The second module  40  includes a low frequency (LF) transducer and a driving circuit assembly  46 , disposed within a housing  54  of the second module  40 . The driving circuit assembly  46  electrically couples the LF transducer  40  to the HF transducer  30 . The LF transducer  40  includes a sound outlet tube  62   b  that is coupled to a LF acoustic transmission tube  93 . The LF tube  93  may function to filter LF signals emitted from the LF transducer  40 . The HF transducer  30  is not driven by a substantially LF input signal. As shown, the LF tube  93  extends from the second module  40  to the first module  30  such that a portion of the LF tube  93  is retained in a hollow section that is formed within the ear mold  96 . The end portion of the LF tube  93  is mated with a second sound port  84   b  of the ear mold  118 . The communication link  50   a  electrically couples the first module  30  to the circuit  46 , and the communication link  50   b  electrically couples the second module  30  to the circuit  46 . 
       FIG. 15  illustrates yet another example of a personal listening device  2 . A first module  30  of the system  2  includes a transducer and a sound tube  62   a  attached to the transducer  30 , disposed within an ear mold  118 . An acoustic tube  93  coupled to the housing  28  may function as a hollow tube to provide LF response modification. Also, the acoustic tube  93  may act as a retrieval member for removal of the module  30  from the ear canal. A communication link  50  parallel to the acoustic tube  93  is coupled to an electrical terminal  88  formed on the rear portion of the transducer  30 . Alternatively, the acoustic tube  93  and the communication link  50  may be integrated as a single unit. As shown in  FIGS. 14-15 , the first module  30  may be an RIE, CIC, or ITC component and the second module may be a BTE, ITE, or a similar device. Other types of devices are possible. 
       FIG. 16  illustrates another example of a module  30 . The module  30  includes dual transducers  32 ,  34 . Electrical terminals  88   a ,  88   b  are formed at the rear portion of the transducers  32 ,  34 . Optional wires (not shown) that extend from the terminals  88   a ,  88   b  are coupled to a driving circuit (not shown). As shown, the transducers  32 ,  34  are mounted either side-by side or end-to-end in order to fit into the ear canal. Each transducer  32 ,  34  comprise an acoustic assembly and a motor assembly mounted in a housing  28 . The housing  28  may be manufactured from any type of moldable or formable material that is corrosion resistant and is bio-compatible for skin contact, including plastic, polycarbonate nylon, liquid crystal polymer (LCP), PEEK, or any other similar materials. Alternatively, part of the housing  28  may be made of magnetically soft metal injection molded material that is capable to function as part of the magnetic return path or electromagnetic shielding for the motor assembly. Such material may be provided to the inner wall of the housing  28 , between layers of the bio-compatible, corrosion resistant material, or outer wall of the housing  28 . Yet in another example, the housing  28  may be made of any material, including but is not limited to Acetal Copolymer or Homopolymer (POM) (Delrin), Acrylic (PMMA), Acrylonitrile Butadiene Styrene (ABS), Cellulose Acetate (CA, CB, CP), Polyamide (Nylons), Polyimide (Kapton), Polycarbonate (PC) (lexan), Polyethylene Terephthalate (PET), Polyetherimide (PEI) (Ultem), Polyetheretherketone (PEEK), Polyethylene, Polyphenylene Oxide (PPO) (Noryl), Polyphenylene Sulphide (PPS), Polypropylene (PP), Polystyrene, Polyvinyl Chloride (PVC), Styrene Acrylonitrile (SAN/ASA), Polyphtalamide (PPA), Polysulphone, polyphenylsulfone (Radel), polybutylene terephthalate (PBT) (Pocan), Polyphthalamide (PPA), Fluoropolymers, Polyarylate, Silicone, or of any similar like. Material may be a blend of these materials or an alloy of these materials. The material may or may not include additives for providing strength and expansion control such as glass content, carbon fiber, or the like. Other materials for providing one or more features, including electrical conductivity, magnetic conductivity, UV stabilization, moisture absorption, moldability, chemical resistance, temperature resistance, flexibility, durability, or hardness, may or may not added to the base material as disclosed above. Other types of materials are possible. An optional non-biocompatible thin film or layer (not shown) may be provided to the housing  28  such that at least a surface of the housing is covered by the film or layer. Alternatively, the housing  28  comprises layers of material, at least one layer of biocompatible material and at least one layer of non-biocompatible material. In another example, the housing  28  comprises an innermost layer that is made of biocompatible material and at least a portion of the layer is provided with a non-biocompatible thin film or layer. The thin film may be made of any material that enhances electromagnetic performance, adhesive, or corrosion characteristics and environmental protection, such as copper, gold, epoxy, primers, or sealant. Alternatively, other types of thin film for surface treatments to enhance adhesion of parts, sealants to encapsulated and protect parts, paints, treatments, thin films for decorative or other reasons may be used. A second sound outlet port  84   b  of the transducer  34  is provided to direct the acoustic energy to the ear canal through a separate tube  62   b  apart from a first sound outlet port  84   a  formed at the transducer  32 . The second tube assembly  62   b  couples to the outlet  84   b  of the transducer  34 . It is mounted in an internal cavity  64  of the housing  28  and then extended through a first end  82  of the housing  28 . An optional electrical filter such as a crossover network may be provided to one or more of the transducers  32 ,  34 . An optional acoustic modification may be provided to the receiver for alternating the frequency response. 
     It will be appreciated that numerous variations to the above mentioned approaches are possible. Variations to the above approaches may, for example, include performing the above steps in a different order. Further, one or more structures may be coupled to the system or module. For example, an electrical cross-over network may be coupled to the connector assembly and adapted for modifying the electrical signal to drive the system or module. In another example, the communication link, the connector assembly, or combination thereof containing acoustical pathways such as tubes, channels, horns, cavities, screens, grids, diaphragms, or the like may be provided and attached to the outlet of the system or module adapted for modification the acoustic response. In yet another example, the top housing of the module may be constructed to be readily removed for cleaning or removing the ear wax. Alternatively, an optional door attached to the top housing in connection with the front volume may be opened for cleaning or removing the ear wax. In another example, the outer surface of the housing may have features for snapping an ear tip, or ear dome, an ear retention clip, or other external accessories. In yet another example, the communication link is reversible wherein the personal listening device and the signal source may connect to any two common ends. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extend as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.