WO1995032600A1

WO1995032600A1 - Noise shielding ear-piece

Info

Publication number: WO1995032600A1
Application number: PCT/CA1995/000307
Authority: WO
Inventors: Reijo Jack Paivarinta
Original assignee: Reijo Jack Paivarinta
Priority date: 1994-05-25
Filing date: 1995-05-25
Publication date: 1995-11-30
Also published as: CA2124231A1; AU2519395A

Abstract

An ear-piece for a telephone receiver or ear defender which includes an ear receiving enclosure having a periphery for juxtaposition to the regions of a user's head surrounding his ear which conforms to the cranial region of a user around his ear.

Description

NOISE SHIELDING EAR-PIECE

FIELD

The present invention relates to an ear-piece for a telephone receiver or ear defender which shields against the entry into the ear of external noise.

BACKGROUND

It is known in the construction of telephone ear-pieces that, even though only one ear is covered by the ear-piece of the receiver, as long as external or ambient noise enters only the uncovered ear, the brain can easily distinguish between the voice of the other caller and the external noise. However, should the external noise enter both ears then the ability of the user to distinguish between the voice of the caller on the other end of the line and the external noise, is impaired.

Ordinary telephone receivers are constructed so that the ear-piece presses against the whole ear sandwiching the ear between the rim of the ear-piece and the bony part of the head surrounding the ear. As a consequence such receivers tend to be uncomfortable and not very efficient at excluding sound in view of the varying topography of that portion of the skull. Moreover, noises from the blood circulatory system tend to be picked up and interfere with the voice of the caller.

U.S. Patent 4,771,454 issued to Wilcox, Jr. discloses a combination ear protector and communications head set in which a thick resilient sealing member is placed between the periphery of the ear-piece and the cranial surface surrounding the ear and is compressed by spring pressure from a headband. Although the complete topography of the peripheral surface of the ear-piece is not disclosed it appears to be simply a flat surface lying in a single plane. Moreover, the resilient strip appears to be about 1 cm in thickness. Such a resilient strip could not possibly seal the entire cranial region around the ear as the variation in topography around the bottom and behind the lower portion of the ear is almost 1 cm.

U.S. Patent 2,669,610 issued to Dent discloses an ear-piece attachment to a telephone receiver which consists of a large sponge cushion with a hole in the middle. There is no disclosure as to how thick the sponge is but it appears to be about 1 cm thick with a width also of about 1 cm. The outer surface of the sponge is flat. Obviously, the Dent receiver attachment abuts a large area around the ear and would not be capable of compressing sufficiently to seal the entire region around the ear.

U.S. Patent 1,615,028 issued to H. Morser On January 18, 1927 recognized the value of an ear-piece that enclosed the ear without pressing against it. however, Morser employs a rigid contact surface around the periphery of the ear-piece that is flat and relatively wide. A flat periphery cannot seal completely around the ear given the large variances in topography.

U.S. Patent 2,989,598 issued to M.L. Touger et al. on June 20, 1961 discloses an ear-piece similar to Morser but having a fluid-filled pliable bag around its periphery. Obviously, any rupture of the bag would not only result in failure of the ear-piece but would be disconcerting for the user.

U.S. Patent 3,666,898 issued to Ferrara on May 30, 1972 discloses the use of a detachable resilient sound absorbing adapter which connects to the ear-piece of a telephone handset. When the handset is pressed against the ear of a user, the deformation of the connector opens a valve which permits the escape of sound into the ear of a user. The adapter although resilient is pressed against the ear of a user.

U.S. Patent 3,938,614 issued to Ahs on February

17, 1976 discloses a flexible air-impervious cushion filled with small plastic balls around its periphery. Again the Ahs ear-piece has a flat and, in addition, a relatively thick cushion. Such a cushion would retain considerable body heat and result in significant heat buildup on the skin against which the ear-piece contacts due to its thickness.

Accordingly, it is an object of the present invention to provide an improved ear-piece for a telephone receiver or ear defender. It is a further object to provide an ear-piece which has improved noise shielding properties. It is yet a further object of the invention to provide an ear-piece which permits relatively little heat buildup around the ear of a user.

SUMMARY OF THE INVENTION

According to the invention there is provided an ear-piece for a telephone receiver or ear defender which includes an ear receiving enclosure having a periphery for juxtaposition to the regions of a user's head surrounding his ear. The variation in topography of the peripheral surface is such as to conform to the cranial surface of a user around his ear. It has been discovered that about 90% of people have a cranial region around their ear with substantially the same topography. The remaining 10% have the same topography except for a variation in a region behind the ear. Thus, it is possible to provide a peripheral surface which is shaped to conform to the topography of the cranial region next to the ear that will fit 90% of the people and a variant of that shape which will fit the remainder of the population. Using an ear-piece which conforms to this shape it is possible to fit either 90% or the remaining 10% of the people and seal around the entire ear using only a thin strip of foam or other sound absorbing resilient material. It is important that the thickness of such a strip be minimized because the high heat insulating properties of high density sound absorbing foam permits body heat to accumulate next to such a strip and create discomfort. By conforming the shape of the ear-piece to the shape of the cranium around the ear it is possible to use a strip of only about 1/8 inches and, thereby minimize the amount of heat build-up.

The peripheral surface may have a slight concavity to match the profile of a user's cheekbone and a protrusion to match the profile of a user's neck region below his ear.

Preferably the periphery rises substantially linearly from a region which is juxtaposed near a top of the ear to a region which extends down the back of the ear near the bottom thereof.

The periphery may have a maximum which extends around a region which corresponds to a user's head around his ear between the bottom of his ear and a region about 3/4 the way to the top of his ear.

The ear receiving enclosure may have a peripheral surface enclosing an ear receiving recess, wherein peripheral surface may be bounded by a rectangle having a width of at least 6 cm and a length of at least

7 cm.

The ear receiving enclosure may have a peripheral surface enclosing an ear receiving recess The peripheral surface may be bounded by a rectangle having a width of 8.0 cm and a length of 10.9 cm. BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, as well as other features and advantages thereof, will be best understood by reference to the description which follows read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation view of a human head showing the region around the ear;

FIG. 2 is a perspective view showing the topography of the head contacting surface of the ear¬ piece;

FIG. 3 is a top view of the peripheral surface of the ear-piece;

FIG. 4 is a graph showing the elevation of the peripheral surface of the ear-piece;

FIG. 5 is a perspective view showing the topography of a large ear-piece showing an alternative shape of a portion thereof designed to fit a portion of the public having a different shape around the ear;

FIG. 6 is a top view of the ear-piece;

FIG. 7 is a graph of elevation versus distance along the periphery of the ear-piece and the alternative portion;

FIG. 8 is a elevation view of a telephone having the ear-piece;

FIG. 9 is an elevation view of a headset using the ear-piece; and FIG. 10 is a circuit diagram showing the noise filter.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS Referring to Figure 1 there is shown a head of a typical user. The more significant regions for the purposes of fitting an ear-piece over the ear are region 11 which is the cheek bone region that protrudes slightly from the surrounding area and region 50 adjacent the jaw bone where there is a depression. The portions from region 11 down to 50 are the most important as they are in front or near the front of the sound reception direction of the ear. Investigations have shown that 90% of all people have a topography around the ear which is substantially the same. The remaining 10% differ only in a region at the back of the ear for ear-pieces that are relatively large. Thus, it is possible to design an ear¬ piece which fits the majority of people and a variation of this shape which fits the remainder of the people should larger ear-pieces be made.

Referring to Figure 2 there is shown the topographical surface of an ear-piece 10 adapted for use with either a telephone receiver ear-piece or on the ear- pieces of an ear defender. The ear-piece 10 has a generally straight portion 13 and a generally semi¬ circular portion 15 with a varying topography. Referring to Figure 2 and proceeding counterclockwise from point "a", the top surface of the ear-piece is slightly concave upwards along the straight portion 13. At the end of the straight portion 13 the elevation returns to that at point "a". Proceeding around the curved portion the height rises substantially linearly with distance reaching a maximum near point "a". Immediately after the maximum, the elevation reduces sharply towards point "a". The topography as measured at 1 cm intervals commencing at point "a" and proceeding around counterclockwise as seen in Figure 3 are given in table I below. TABLE I

Position Height (mm) a 7.0 b 7.0 c 6.0 d 5.75 dl 5.50 e 5.75 f 6.0 g 6.5 h 6.5 i 6.0 j 6.0 k 6.5

1 7.0 m 8.0 n 9.0 o 9.5

P 10.5 q 12.0 r 13.0 s 14.0 t 15.0 u 17.0 ul 17.5

V 17.0 w 9.5

The points dl and ul are not on the 1 cm intervals but mark minimum and maximum, respectively.

The dimensions across the ear-piece 10 are as indicated in Figure 3. Here a line 21 has been drawn along the outside surface of the straight portion 13 and then a parallel line 23 through the opposite extremity 17 of the ear-piece 10. Lines 25 and 27 perpendicular to the foregoing two lines are then drawn through the extremities on the left and right hand side, respectively, of Figure 3. Next diagonals are drawn through the resulting rectangle and lines from the point of intersection perpendicular to each side of the rectangle. Line segments 12 and 14 are both equal to 3.1 cm while line segments 20 and 22 are both 3.7 cm. Line segments 16 and 18 are both 4.85 cm while line segments 24 and 26 are also 4.85 cm.. The length of the rectangle which bounds the ear-piece 10 has a width of 6.3 mm and a length of 7.5 cm. This is a value within which most human ears would fit taking the thickness of the periphery to be about 1/2 cm.

In use the maximum at ul fits into the depression next to the jaw and the opening fits over the ear. In this position the topography of the ear-piece of Figure 2 closely matches the region of the head around the ear for almost all users regardless of ethnic origin or other parameters.

Referring to Figure 4 and 5 there is shown an alternative embodiment 30 of the ear-piece which is larger than that of Figures 2 and 3. It will be seen that the straight portion 32 beginning at point A has a more pronounced dip where it fits over the jaw bone and a more pronounced dip 33 before arriving at the local maximum 34. Variant 36 has an optional higher region to fit certain skull types that depart from the norm. Such types comprise about 10% of the population. Again the ear-piece 30 fits within a rectangle 39 such that the intersection of the diagonals of the rectangle and the lines bisecting its sides coincide and are at the center of the ear-piece 30. The lengths of line segments 32 and 34 are each 4.0 cm, the lengths of line segments 40 and 42 are each 5.4 cm, the lengths of line segments 36 and 38 are 4.8 cm, and lines 44 and 46 are each 5.0 cm. The width of the rectangle 39 bounding the ear-piece 30 is 8.0 cm while the length is 10.9 cm. The topography of the ear-piece is shown in

Figure 7 in which measurements are taken every 1 cm as one proceeds from point A clockwise. The variant is shown in dotted outline between points J and W. Tables containing the elevation of the topography as measured from a convenient baseline are shown in Table II below:

TABLE II

Position Height (mm) Height(mm) (Alternate)

A 3.5

B 3.0

C 4.3 D 8.5

E 13.0

F 15.5

G 15.0

H 14.0 I 13.5

J 15.8

K 19.0 21.0

L 19.0 24.0

M 18.5 27.0 N 18.5 28.5

0 18.5 29.0

P 18.0 28.0

Q 17.5 25.0

R 17.0 23.0 S 15.5 20.0

T 14.5 18.0

U 13.5 15.5

V 12.5 13.0 W 11.5 X 11.3

Y 10.0 Z 9.2 Al 8.1 Position He ight (mm) Height (mm) (Alternate)

Bl 8 . 0

Cl 6.2

Dl 5. 5

El 4 . 5

There are obviously other sizes that could be selected with the primary criterion being that the ear¬ piece fit over the ear and not be so large that it becomes impractical. The regions between points "g" and point "t" in Figure 4 and points "A" and "H" in Figure 7 are the most critical as these correspond to the portion fitting over the cheek bone region 11 (see Figure 1) and in the bottom-most depression 50 adjacent the jaw bone of a user.

In applications requiring high noise rejection it is important to have the ear-piece periphery conform closely with the region of the user's head around the ear. Clearly, one can utilize to some extent a strip of sound absorbing foam or the like around the periphery to compensate for a lack of fit but there is obviously a limit to the extent of compensation possible. A second disadvantage is that large diameter cushions tend to insulate the region they abut and allow heat buildup around the user's ear making the ear-piece uncomfortable. By providing an ear-piece which conforms to the region around the ear of the user's head, one can utilize a thin strip of cushion material rather than one which is unduly large, and thereby avoid significant heat buildup.

Referring to Figure 8 there is shown a telephone receiver having an ear-piece whose periphery is in the shape of the ear-piece of Figures 2 to 4. In this case the ear-piece shields one ear only against the entry of noise. A strip of high density sound absorbing foam 50 of about 1/8 inches in diameter extends around the periphery. The natural ability of the human mind to reject noise which enters only one ear allows such a receiver to be used in noisy environments.

Referring to Figure 9 there is shown an ear defender with one ear-piece the shape of Figures 2 to 4 and the other being its mirror image. The purpose of such ear defenders is simply to protect the eardrums against excessive noise. A much higher attenuation of noise is experienced using the conformal shape of the ear-piece of the present invention.

Recognizing that the range of the average female voice is from 130.8 to 523 Hz while the for a male voice is 65.4 to 260 Hz, it is possible to utilize a band pass filter to limit the noise that can interfere with audio. In addition, one can utilize a standard noise cancelling microphone attached to the telephone receiver to cancel out the background noise from the telephone receiver. Figure 10 shows the utilization of a microphone 44, an input amplifier 40, a low pass filter all in series with that portion of a telephone receiver 46 that transmit voice over telephone lines. Such an arrangement produces a telephone receiver that is very comfortable to a user and has an excellent noise blocking capability as well as a noise free receiver.

Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modification or embodiments as fall within the true scope of the invention.

Claims

I CLAIM :

1. An ear-piece for a telephone receiver or ear defender, comprising:

an ear receiving enclosure having a periphery for juxtaposition to the cranial region of a user surrounding his ear which conforms to the topography of that region.

2. An ear-piece according to claim 1, wherein said periphery has a slight concavity to match the profile of a user's cheekbone and a protrusion to match the profile of a user's neck region below his ear.

3. An ear-piece according to claim 2, wherein the periphery rises substantially linearly from a region which is juxtaposed near a top of the ear to a region which extends down the back of the ear near the bottom thereof.

4. An ear-piece according to claim 3, wherein the periphery has a maximum which extends between a bottom of his ear and about 3/4 of the way around the back of the ear to the top thereof.

5. An ear-piece according to claim 1, wherein said ear receiving enclosure has a peripheral surface enclosing an ear receiving recess, said peripheral surface bounded by a rectangle having a width of at least 6 cm and a length of at least 7 cm.

6. An ear-piece according to claim 1, wherein said ear receiving enclosure has a peripheral surface enclosing an ear receiving recess, said peripheral surface bounded by a rectangle having a width of 8.0 cm and a length of 10.9 cm. 7. An ear-piece according to claim 5, wherein the periphery is substantially circular with one side being substantially straight and having a longest dimension through its center of approximately 7.5 cm and a shortest dimension through its center of 6.2 cm and the elevation of said peripheral surface taken in 1 cm sectors around its outermost edge as measured from an arbitrary planar base level having the following approximate measurements:

Height (mm)

7.0

6.0

5.75

5.50

5.75

6.0

6.5

6.0

6.5

7.0

8.0

9.0

9.5 10.5 12.0 13.0 14.0 15.0 17.0 17.5 17.0

9.5 8. An ear-piece according to claim 4, wherein the periphery is substantially circular except for a straight portion which is adapted for positioning over the cheekbone and with a longest dimension and through its center of approximately 10.9 cm and a shortest dimension through its center of 8.0 cm and the elevation of said peripheral surface taken in 1 cm sectors around its outermost edge as measured from an arbitrary planar base level having the following approximate measurements:

Height (mm) 3.5 3.0 4.3 8.5 13.0 15.5 15.0 14.0 13.5 15.8 19.0 19.0 18.5 18.5 18.5 18.0 17.5 17.0 15.5 14.5 13.5 12.5 11.5 11.3 10.0 9.2 8.1 Height (mm) 8 . 0 6.2 5. 5 4 . 5

9. An ear-piece according to claim 4, wherein the periphery is substantially circular except for a straight portion adapted for positioning over the cheekbone of a user and having a longest dimension and through its center of approximately 10.9 cm and having a shortest dimension through its center of 8.0 cm and the elevation of said peripheral surface taken in 1 cm sectors around its outermost edge as measured from an arbitrary planar base level having the following approximate measurements:

Height (mm)

3.5

3.0

4.3

8.5 13.0 15.5 15.0 14.0 13.5 15.8 21.0 24.0 27.0 28.5 29.0 28.0 25.0 23.0 20.0 18.0 Height (mm)

13. .0

11. .5

11, .3

10. .0

9. .2

8, .1

8, .0

6, .2

5, .5

4. .5