US 3632902 A
A sound reflector-modifier particularly useful to the hard of hearing for improving the quality and clarity of sounds received and reproduced by hearing aids and comprising in combination a sound reflective surface for receiving direct sound waves from a source and for reflecting them into an enlarged end of a sound passage leading to a sound chamber communicating with a sound pickup of a hearing aid.
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Description (OCR text may contain errors)
United States Patent Butts Dvorsky Gorike Beaudry Lehr Thompson Salomon et a1. Hinman Primary Examiner-Kathleen 1-1. Claffy Assistant Examiner-Thomas L. Kundert Attorney-Harris, Kiech, Russell & Kern ABSTRACT: A sound reflector-modifier particularly useful to the hard of hearing for improving the quality and clarity of sounds received and reproduced by hearing aids and comprising in combination a sound reflective surface for receiving direct sound waves from a source and for reflecting them into an enlarged end of a sound passage leading to a sound chamber communicating with a sound pickup of a hearing aid.
PATENTED JAN 4 I972 SHEET 2 BF 2 lime/woe SOUND REFLECTOR-MODIFIER FOR HEARING AID MICROPHONES he invention relates generally to apparatus for improving the sound reproduction characteristics of microphones, and more particularly to a device adaptable for use in combination with a hearing aid to improve the quality and clarity of the sound received and transmitted by the hearing aid to the auditory nerves.
Persons with impaired hearing have extreme difficulty in comprehending and distinguishing the diverse sounds around them. Understanding the human voice is particularly exasperating, and numerous problems arise which are virtually nonexistent for the person with normal hearing. Among these problems are distracting background noise, lack of clarity, poor fidelity, confusing echos and reflections, pitch obscurity, distortion, poor quality, and a general lack of awareness of sound presence. Various attempts have been made to build hearing aid devices which overcome these problems. Some success has been achieved in obtaining increased amplification and decreased microphone size, but the other problems mentioned above continue to frustrate the partially deaf in their quest to achieve and surpass the threshold of sound comprehension.
Accordingly, it is a primary object of the present invention to provide a sound reflector-modifier which helps to overcome the aforementioned sound comprehension problems of the partially deaf.
Another object is to provide a sound reflector-modifier which is adaptable for mounting on the microphone housing of conventional hearing aid devices or alternatively may be manufactured integral with such housings.
Still another object of the invention is to provide a sound reflector-modifier which will increase the fidelity and sound clarity of the sound waves generated by a human voice and received and developed by a hearing aid device, to enable a person with a hearing deficiency to intelligibly discern and distinguish words generally, and, in particular, words incorporating the aspirated sounds associated with the letter h, the letters p, t, and k, as well as other letter combinations which incorporate the expiratory breath puff in their formation.
A further object is to provide a sound reflector-modifier of the foregoing character including a sound-directing and concentrating passage between a sound reflective surface and a sound pickup (microphone) of a hearing aid, the reflective surface receiving direct sound waves from a sound source and reflecting same into the passage.
Still another object of the invention is to provide a sound reflector-modifier of the foregoing character for use with a hearing aid device in which the sounddirecting passage has an enlarged end for positioning adjacent the human chest to collect and gather sound waves which have been reflected from the chest.
A still further object of the invention is to provide a sound reflector-modifier of the foregoing character in which a filtering shield is provided to shield the microphone from harsh direct sound waves and extraneous sounds so that only sound waves from the reflective surface are allowed to pass through the sound passage.
Another object of the invention is to provide a sound reflector-modifier of the character described having a sound chamber in the end of the sound-directing and concentrating passage adjacent the microphone to permit expansion of the sound waves before striking the microphone.
Still another object of the invention is to provide a sound reflectormodifier of the foregoing character with elements in the sounddirecting passage which combine to modify and refine the sound which passes therethrough to the microphone.
A further object of the invention is to provide sound reflector-modifiers of the foregoing character having sound-directing passages of designs which achieve optimum clarity, fidelity, and quality of sound waves received by microphones of as sociated hearing aid devices.
A still further object of the invention is to provide a sound reflector-modifier of the foregoing character which is inexpensive, easy to make, and durable, and which may be individually calibrated for the user.
The foregoing as well as other objects and advantages of the present invention may be more clearly understood by reference to the following detailed description and accompanying drawings, which together illustrate by way of example only various forms of sound reflector-modifiers for microphones embodying the present invention.
In the drawings:
FIG. I is a perspective view of one: form of the invention showing a person using a conventional hearing aid device with a sound reflector-modifier mounted on the microphone and amplifier housing thereof;
FIG. 2 is a front view of the modifier of FIG. 1 with a portion cutaway;
FIG. 3 is a sectional view of the modifier of FIG. 1 taken along line 3-3 of FIG. 2;
FIG. 4 is a perspective view of-the modifier of FIG. 1 shown from a threequarter front position;
FIG. 5 is an alternate form of the modifier of FIG. 1 shown from the same view as FIG. 4;
FIG. 6 is a front view of another form of a sound reflectormodifier mounted on a housing for a microphone of a hearing aid device;
FIG. 7 is a side sectional view of embodiment of FIG. 6 taken along line 7-7; and
FIG. 8 is another embodiment of the modifier mounted on a hearing aid microphone housing having a sound-receiving aperture on a face thereof.
As previously indicated, my sound reflector-modifier is particularly useful in combination with conventional hearing aid devices. In particular, when so combined, it has proven under actual test conditions with those of impaired hearing to dramatically reduce the effects of background noise which has heretofore cluttered and distracted from and sometimes precluded detection of desired sound waves. Moreover, my sound reflector-modifier when employed in conjunction with a conventional hearing aid device has proven in such instances to materially improve the clarity and fidelity of the sound waves reproduced by the hearing aid device and received by the listener. In short, whereas when the partially deaf utilize conventional hearing aid appliances they are unable to clearly distinguish the pitch of various tones, are confused by echoes and reflections and background noise and are unable to distinguish certain breath tones; when my modifier is added to such hearing aid devices they are immediately able to clearly distinguish and recognize such tones and on actual tests have reported to me substantial elimination of problems produced by background noise, echoes, reflections, and distortions.
Generally speaking, my sound reflector-modifier includes an ear member in combination with a sound reflective surface. In the drawings, the modifier, ear member, and reflective surface are designated by the numerals 10g 12, and 14 respective' ly.
When the sound reflector-modifier 10 is utilized with a hearing aid device, as for example in FIG. 1, the ear member 12 is mounted on the microphone housing 16 of the device to face the sound reflective surface 14 (here the chest of the listener) and to communicate with the microphone in the housing through an aperture 18 (see FIG. 2). Sound waves from a source strike the sound reflective surface 14 and rebound into the ear member 12 where they are concentrated, directed, and modified as they travel through a sound passage 20 in the ear member to the microphone. At the microphone and in circuitry of an amplifier circuit associated therewith, the sound waves are converted into electrical signals, amplified and transmitted by an electrical lead 22 to an earpiece 24 (speaker) in the ear of the listener. In the earpiece 24 the electrical signals are reconverted into sound waves which act upon the auditory nerves in the ear and head of the listener to produce the sensation of sound.
It bears emphasizing that my invention utilizes sound waves reflected from a sound reflective surface into a sound passageway leading to the microphone of the hearing aid device. This is to be distinguished from hearing aid appliances which collect direct sound waves from a sound source. In my invention, 1 have found through testing of various hearing aid devices with various persons having impaired hearing that the combination of my invention including the sound reflective surface 14 and the sound directing and concentrating passage designed such that only reflected waves are received at the microphone, has the unexpected result of materially improving the clarity and fidelity of the sound waves reproduced by the hearing aid device and transmitted to the ear of the partially deaf listener while substantially reducing the distracting effects of background noise, overcoming pitch obscurity, the effects of distortion, and possibly of most importance allowing the listener to clearly distinguish vocal sounds which he or she has heretofore not been able to distinguish such as sounds associated with letters h, p, t, and k.
The exact manner in which my invention operates upon the sound waves as they strike the sound reflective surface and are gathered, directed, and modified in the sound passage leading to the microphone is not fully understood. However, from my practical tests, it appears that the use of the sound reflective surface together with my sound passage, substantially eliminates, at least as far as the listener is concerned, sound waves which are out of phase with each other reaching the microphone, preclude background noise from reaching the microphone with sufficient volume to have any noticeable effect upon the desired sound waves transmitted to the ear of the listener. Moreover, through gathering, reflection, concentration, and expansion of the sound waves in the sound passage, my invention improves the clarity and fidelity of the desired sound waves received by the microphone and reproduced by the hearing aid device to enable the partially deaf listener to achieve and surpass his or her threshold of sound comprehension in a manner heretofore unattainable with known hearing aid applicances. Since I am not certain as to the exact mode of operation of my invention and exactly how it achieves the indicated results, the explanation offered herein as to the inner operation of my invention upon the sound waves should not be considered as limiting upon my invention but simply as being the way in which my invention appears to me to operate and produce the desired results.
Referring now more particularly to the preferred embodiment of my invention illustrated in FIGS. 2, 3, and 4, the ear member 12 extends vertically from a basemember 26 and includes upper and lower portions 28 and defining the sound passageway 20. The base 26 is generally rectangular, includes openings for receiving control dials for the hearing aid circuitry, and is designed to fit tightly over a top of the housing 16 including the aperture 18. Additional sealing means, such as an adhesive, may be incorporated to secure the ear member to the housing if desired or, alternatively, the ear member 12 may be formed integral with the housing 16 over the aperture. In either case, the sound passageway 20 communicates directly with the aperture 18 and the microphone within the housing.
In the illustrated form, the ear member 12 resembles a folded funnel. In this regard, the lower portion 30 of the ear member 12 extends above the base 26 at an angle toward the reflective surface 14. The upper portion 28 of the ear member 12 extends upwardly and forwardly from the lower portion 30 such that an upper lip 32 thereof contacts the sound reflective surface 14, which in the exemplary form is the listeners chest, with the central axis of the upper portion substantially perpendicular to the reflective surface and to the central axis of the lower portion.
In my experimentation, the shape and location of the open ing 31 of the passage 20 adjacent and facing the reflective surface I4 has been found to be of particular importance in improving the quality of the sound passing to the microphone and reproduced by the hearing aid device. In this regard, it has been found highly desirable to limit the sound waves entering the passageway 20 to those that rebound from the reflective surface 14. In the illustrated form, this object is achieved by shaping the opening 31 in the form of an enlarged rectangle, the edges of the rectangular opening being determined by the upper lip 32 which extends outward beyond an abbreviated lower lip 34. The upper lip 32 actually contacts the reflective surface 14 while the lower lip 34 is spaced therefrom. As illustrated in FIG. 3, such an arrangement of the upper and lower portion of the ear member 12 in combination with this sound reflective surface 14 defines a chasm therebetween. The chasm permits sound waves rebounding from the surface to be reflected into and gathered by the enlarged open end 31 of the passageway 20 and in practice appear to effectively limit the waves entering the passageway to such reflected waves. While such a rectangular-shape opening is preferred for the opening 31, the opening may take other forms so long as they permit the upper portion 28 to act as a shield in filtering all the direct waves and most of the undesired indirect and extraneous sound waves from traveling into the passage 20.
The configuration of passage 20 between the opening 31 and an opening 35 at the base of the lower portion 30 communicating with the aperture 18 is also particularly important in assuring that sound waves of the preferred quality are received by the microphone within the housing 16. A preferred shape for the passage 20 is shown in FIGS. 2, 3, and 4 as being a modified hourglass shape. With the hourglass-shaped passage 20, sound waves rebounding from the reflective surface 14 are gathered through the opening 31 and directed by the upper funnel-shaped portion of the passage toward an intermediate portion 36 of relatively small cross-sectional area. The sound waves in entering the intermediate portion 36 are reflected and rebound from and between the sides of the passageway and are concentrated. From the intermediate portion 36, the concentrated sound waves enter the lower portion of the passageway 20 where they are allowed to expand prior to passage through the aperture 18. In this regard, the lower portion of the passageway 20 below the intermediate portion acts as a sound chamber. Dimensionally, the sound chamber has a shorter axial length and a smaller cross-sectional area than the upper portion of the hourglass passage adjacent the surface 14. In addition, the axes of the two openings of the hourglass passage 20 are displaced approximately from each other.
While the invention is not limited to the specific dimensions and shape of the sound passage 20 just described and illustrated, the quality, clarity, timbre, and pitch have been improved the most by employing a sound passage 20 having an enlarged end defined by the upper portion 28 which connects through a constricted intermediate portion 36 for focusing and concentrating the sound, to a sound chamber defined by the lower portion 30, which sound chamber communicates with the microphone through the aperture 18.
Sometimes the configuration of the passage 20 is determined in part by the location of the aperture 18 in the housing 16. For example, the embodiment shown in FIG. 8 includes an aperture 18 in a front face of the housing 16. In that case, the ear member 12a is located on the front of the housing and defines a more conventional hourglass-shaped passage 20a with its axis inclined slightly upward. Similar adaptations of the ear member and sound passage therein may be made to facilitate use of the invention with microphones having variously sized apertures in various positions on the housing without diminishing the salutary acoustical results.
It will be appreciated that the quality of sound received and reproduced by the hearing aid device is affected by many factors as the waves rebound from the reflective surface 14 through the passage 20 and the aperture I8 to the microphone. I have discussed above the importance of the shape and size of the passage opening adjacent the reflective surface 14, as well as the spatial relationship of the upper and lower lips 32 and 34 with the reflective surface 14. The importance of the sound-directing passage configuration has also been discussed, including the structural details of the preferred passage 20 having a modified hourglass shape. A further factor affecting the quality of the sound is the aperture 18. As shown in the drawings, a conventional filter member such as a grille 33 is attached to the housing and completely fills the aperture opening. It has been determined by experimentation that the grille 38 only partly performed its task of filtering and damping extraneous and strident elements of the sound passing through the aperture to the microphone. Accordingly, in a preferred form of my invention a perforated tape 40 made, for example, from plastic and/or aluminum foil may be suitably attached under the lower portion 30 of the ear member 12 to completely cover the grille 38. In practice subtle fine tuning has been obtained by varying the size, number, and location of the perforations in the tape 40. For example, and as shown in FIG. 5, the quality of sound passing through the aperture 18 and grille 3b to the microphone was improved in some instances by placing a tape 40 having a single circular perforation in the center thereof over the grille and by using an ear member llZb in which the lower portion 30b and the upper portion 23b define a funnellike passage 20b having its small opening positioned to communicate through the circular perforation to the aperture 118, with the large opening of the large funnellike passage being designed, as before, for location in the vicinity of and substantially facing the reflecting surface 14. The shape and position of the upper and lower lips 32b and 34b are similar to that of the preferred embodiment discussed above, such that the axes at the opposite ends of the funnellike passage are substantially normal to each other.
Referring to FIGS. 6 and 7, it was found experimentally that by providing a modified configuration for the ear member 12c, and by interposing various additional elements in the modified sound-directing passage 20c, it was possible to introduce additional factors which would affect the quality of the sound being transmitted through the aperture 118 to the microphone. More particularly, the lower portion 30c of the ear member 12c in the embodiment includes a first rectangular box 42 with its back and sides secured as by adhesive and extending from the corresponding back and sides of the housing 16. The upper end of the box member 42 is closed by a panel 44 respectively perpendicular to the back and sides thereof and extending across and within the passage 200. The open side of the reflector box 42 faces the reflective surface 114 for reception, concentration, and reflection of sound waves coming from the reflective surface. Two sound focusing and filtering louver members 46 are disposed in parallel position across the reflector box 42 just below the panel 44 with the front edges being inclined slightly upward to direct sound toward the aperture. An inner member or cap 4% having a spherical quadrant shape is located in the reflector box 42 below the louvers and is designed to be fitted around the aperture 18 with its opening facing toward the reflective surface 14. The cap 48 functions to collect and concentrate the sound waves and to direct them through the aperture 1%. The size, shapes, and positions of the louvers and cap within the part of the passage 20c defined by the lower portion 34% may be varied in order to achieve the optimum clarity and fidelity for the individual user.
In he embodiment of FIGS. 6 and 7, it was found helpful to cover with a filter cloth 50 the subchambers formed by the reflector box 42, louvers 46, and the cap 48. The filter cloth 50 serves to temper the glare of the sound waves as they bounce off the reflective surface 14 and are reflected and modified in the passage 20c on their way toward the aperture 18.
In the embodiment of FIGS. 6 and 7, the upper portion 28c of the ear member 120 is located directly above the lower portion 30c and includes a second box reflector 52 wider than the first reflector box 42 with its sides 54 and top 56 depending outwardly for gathering and concentrating the sound waves rebounding from the reflective surface 14.
Since in the embodiment of FIGS. 6 and 7, the ear member does not extend beyond the front face of the housing 16 (in contrast with the other embodiments), it is necessary to pro vide a protruding support on the front face of the housing such as a spacer block 5% to produce the desired sound chasm outside the sound passageway Zflc to capture waves rebounding from the surface 14. Thus as illustrated in FIG. 7 with the block 5%, the top 60 of the upper portion 280 and the block contact the reflective surface 14, define the chasm and thereby produce sufficient clearance between the passage 20c and the surface I4 for gathering those sound waves rebounding from the surface.
It will be appreciated from the foregoing that my invention modifies, concentrates, filters, dampens, and refines the sound waves passing through the passage 20 and the aperture 18 to the microphone to produce sound of increased fidelity and improved clarity and quality. In addition, the ear member 12 may include a sound passage of various optimum configurations as determined experimentally wherein elements of dif ferent sizes and shapes are chosen and positioned to optimize the acoustical characteristics of the device for the individual user.
Moreover, although my invention has been described in combination with a housing in a hearing aid device suspended over the chest ofa listener, its use is not to be limited to such a setting or such a combination. In fact, my invention including the ear member and sound reflective surface may be usefully employed wherever it is desired to modify sound reception of a microphone and the sound reproduced by associated circuitry and speaker systems.
Furthermore, while preferred embodiments of my invention have been described in some detail herein, changes and modifications may be made in the illustrated forms without departing from the spirit of my invention. It is therefore intended that my invention be limited in scope only by the terms of the following claims.
1. A hollow generally ear-shaped sound reflector-modifier for capturing only reflected sound waves rebounding from an immediately adjacent sound reflective surface and for directing the captured reflected sound waves to a hearing aid microphone enclosed in a case in a manner which increases the fidelity and clarity of the sound waves, comprising:
a first housing portion including outwardly and forwardly depending sides facing said sound reflective surface, an upper edge directed toward said sound reflective surface with a forward upper lip immediately adjacent thereto, a front face below said upper edge facing said sound reflective surface and relieved below said upper lip away from said sound reflective surface, and a back face rearward of said front face for shielding said front face from direct sound waves from a source rearward of said back face whereby said front face combines with said sound reflective surface to form a chasm for capturing only reflective surface;
a second housing portion extending from said first housing portion;
means for mounting said second housing portion on said case over an aperture open to said microphone such that the microphone is shielded from said direct sound waves from said source; and
sound passageway means for directing the captured reflected sound waves from said chasm to said microphone while increasing the fidelity and clarity of said reflected sound waves, said passageway means having a first open end in said front face immediately below said upper lip and comprising substantially the entire area of said front face for receiving sound waves rebounding from said sound reflective surface, a second open end in said second portion over said aperture open to said microphone, and means defining a substantially spherical quadrant-shaped member in said second portion including said second open end and an opening to said sound reflective surface.
2. The sound reflector-modifier of claim I further including in said second housing portion sound wave deflecting louvers inclined relative to the direction of reflected sound waves rebounding from said sound reflective surface into said chasm for directing said reflected sound waves toward said aperture.
3. A hollow generally ear-shaped sound reflector-modifier for increasing the fidelity and clarity of sound waves received by a hearing aid microphone housed in a case supported against the chest of its wearer, comprising:
a lower housing adapted for mounting on said case over an aperture leading to said microphone to shield said microphone from direct sound waves;
an upper housing extending upward from and forward of said lower housing toward said chest and including an upper edge having a forward upper lip engaging said chest, a front face below said upper edge facing said chest and relieved below said upper lip away from said chest, and a back face rearward of said front face for shielding said front face from direct sound waves from a source rearward of said back face whereby said front face combines with said chest to form a chasm for capturing only reflected sound waves rebounding from said chest; and
a passageway through said upper and lower housings for directing the captured reflected sound waves from said chasm to said microphone while increasing the fidelity and clarity of said reflected sound waves, said passageway having a first open end in said front face immediately below said upper lip and comprising substantially the entire area of said front face for receiving sound waves rebounding from said chest, a second open end axially displaced about from said first open end and being in said lower housing over said aperture in said case, an axially elongated funnel-shaped upper passage portion including said first open end and extending therefrom rearwardly and downwardly to an intermediate passage portion of relatively small cross-sectional area, and a lower passage portion extending from said intermediate passage portion in said lower housing and including said second open end and having a shorter axial length and a smaller cross-sectional area than said upper passage portion.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. R 5,632,902 I .Iannary L, l212 lnvent fl JOHN J WAHLER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 6 line 51, after "only" insert "reflected sound waves rebounding from said sound Signed and sealed this 6th day of June 1972.
EDWARD M.FLETC.HER,JR. ROBERT GOTTSCHALK Attesting Officer I Commissioner of Patents FORM P040550 1 uscoMM-Dc 60376-P69 US. GOVERNMENT PRINTING OFFICE 1 I969 0-366-334