Earplugs with built-in thermometer

Abstract

An earplug consists of a housing, a thermometer module, and a speaker module. The housing defines a channel with an opening. The thermometer module is located within the housing and receives infrared radiation from the eardrum via the channel. The speaker module is also located within the housing and generates sound waves that propagate through the channel toward the eardrum. The speaker module works in conjunction with the housing and the thermometer module to create separate infrared radiation paths and sound wave paths within the channel, through which the infrared radiation from the eardrum and the sound waves generated by the speaker module, respectively, propagate.

Description

TECHNICAL AREA

[0001] The present invention relates to an earplug and in particular an earplug with a built-in thermometer. BACKGROUND

[0002] As in Fig. As can be seen in Figure 1, a conventional earplug comprises a front housing 11, a rear housing 12, a loudspeaker 13, a battery 14, and an earpiece 15. The front housing 11 is connected to the rear housing 12 and has a main section 111 that interacts with the rear housing 12 to define a cavity 10, and a neck section 112 connected to the main section 111. The neck section 112 defines a sound channel 113 within the cavity 10, which is spatially connected to the cavity 10 and has an opening facing away from the cavity 10. The loudspeaker 13 is located in the cavity 10 and generates sound waves that travel through the sound channel 113. The battery 14 is located in the cavity 10 and is electrically connected to the loudspeaker 13. The earpiece 15 is attached to a distal end of the neck section 112 of the front housing 11.

[0003] Recently, additional functions have been expected of earplugs. For example, in addition to emitting sound waves, an earplug may be equipped with a built-in eardrum temperature sensor that receives infrared radiation from the user's eardrum to monitor the user's body temperature.

[0004] However, if the tympanic temperature sensor is located in the sound channel 113, the sound waves propagating through the sound channel 113 are obstructed by the tympanic temperature sensor, thus impairing the sound quality of the earplug.

[0005] If the tympanic membrane temperature sensor is positioned in the cavity 10 so as not to obstruct the sound channel 113, the sensor is located away from the opening of the sound channel 113 through which the infrared radiation from the eardrum enters the cavity 10. Consequently, the sensor may receive a large amount of radiation that is irrelevant to the eardrum temperature, such as infrared radiation from an inner wall of the neck section 112 of the front housing 11, resulting in an inaccurate determination of the user's body temperature.

[0006] US Patent 2021 / 0302242 A1 discloses an ear thermometer with a probe containing an infrared sensor for non-contact measurement of the eardrum temperature of a target person, which is attached to the target person's eardrum. The probe comprises a probe body that is inserted into the eardrum, a housing that supports the probe body, and an in-ear earpiece that is attached to the probe body and makes contact with it within the eardrum. The earpiece has a base with an engagement part that engages with the probe body and has a partially hollow, conical shape, as well as a substantially cylindrical tip that is provided at one end of the base and extends away from the housing in one direction. The base and tip are formed in one piece from a flexible material. The outer diameter of the tip is smaller than the maximum outer diameter of the base.

[0007] From US patent 2013 / 0218022 A1, personal protective equipment with integrated physiological monitoring is known. The personal protective equipment is designed as an in-ear device (such as hearing protection and / or communication devices) incorporating one or more physiological sensors for the early detection of heat-related illnesses. The personal protective equipment includes, for example, a temperature sensor and a speaker integrated into such an in-ear device.

[0008] From WO 2017 / 024689 A1, a headphone is known which comprises the following: A main headphone with a loudspeaker element configured to transmit sound to the external auditory canal. A protruding element configured to extend from the main headphone and into the external auditory canal. A photoelectric sensor. The photoelectric sensor and the protruding element are arranged in a spatial relationship to each other that enables the photoelectric sensor to emit light to illuminate an inner wall of the external auditory canal and to receive light reflected from the inner wall of the external auditory canal.In this way, the light emitted by the photoelectric sensor can enter the outer ear canal via the protruding part in the main earphone and be reflected by the inner wall of the outer ear canal, whereby physiological information of a human body, such as heart rate information, can be determined according to the optical information of the inner wall of the outer ear canal by detecting a change in the light intensity of the reflected light.

[0009] From WO 2010 / 098912 A2, a monitoring device is known that is designed to be placed on a person's ear. The monitoring device comprises a base, an earpiece housing extending outwards from the base and designed to be positioned in a person's ear, and a cover that covers the earpiece housing. The base includes a loudspeaker, an optical emitter, and an optical detector. The cover comprises a translucent material that is in optical communication with the optical emitter and the optical detector and serves as a light guide to direct light from the optical emitter into the ear canal of the person wearing the device at one or more predetermined points, to collect light outside the earpiece, and to deliver the collected light to the optical detector.

[0010] From DE 198 27 343 A1, a device for performing measurements in the ear is known, featuring a positioning aid that enables correct alignment of the device's measuring tip in the user's ear canal. The device comprises a radiation source, particularly one emitting in the visible range, a photodetector suitable for this radiation, an associated evaluation unit, and optionally a display unit to show the alignment of the measuring tip in the ear canal. The ear canal is illuminated by the radiation source, with a portion of the radiation being backscattered into the measuring tip and detected by the photodetector. The detected radiation power depends on the average distance between the reflecting tissue and the measuring tip, with a minimum radiation power corresponding to correct alignment of the measuring tip with the posterior ear canal and thus with the eardrum.The output signal of the photodetector preferably controls the frequency and / or volume of an acoustic signal that informs the user of the best orientation of the measuring tip, thus improving the repeatability of the measurement results.

[0011] From US patent 11,571,132 B2, a measuring device, a measuring instrument, a measuring system, a server, an analysis method, a storage medium, and a data structure are known. The measuring device comprises: a metal tube having a first end and a second end; a measuring unit arranged on the side of the first end of the metal tube and capable of measuring electromagnetic radiation incident from the second end of the metal tube; an audio output unit configured to emit sound; and a first path and a second path to the first end of the metal tube for sound emitted by the audio output unit, wherein the first path and the second path are of different lengths.

[0012] From JP 2022-008652 A, a portable device is known that is capable of measuring a user's body temperature and other vital parameters in a variety of situations. The portable device is designed to be inserted into the ear canal. By providing an infrared thermometer at the innermost end of the ear, it is ensured that the thermometer is positioned as close as possible to the eardrum to determine body temperature.

[0013] From WO 2022 / 213346 A1, an earphone is known which comprises the following: a housing forming an audio opening, wherein the audio opening is configured such that, in a wearing position of the earphone, it is positioned within or facing the ear canal of a wearer; a loudspeaker positioned within the housing, wherein the loudspeaker has a diaphragm facing the audio opening and forming an audio channel between the diaphragm and the opening; a body temperature measuring module arranged within the audio channel, wherein the body temperature measuring module has a reflector and a temperature sensor, wherein the temperature sensor is configured to receive infrared light transmitted through the audio opening and reflected by the reflector. SUMMARY

[0014] One objective of the present invention is therefore to provide an earplug that eliminates at least one of the disadvantages of the prior art.

[0015] According to the present invention, the earplug is designed to be inserted into a user's ear canal and comprises a housing, a thermometer module, and a loudspeaker module. The housing forms a cavity and a passage / channel located therein. The passage / channel is spatially connected to the cavity and has a passage / channel opening located distal to the cavity and spatially connected to the ear canal. The thermometer module is shown within the housing and is designed to receive infrared radiation from the user's eardrum via the passage / channel in order to determine the user's body temperature. The loudspeaker module is arranged within the housing and operates by generating sound waves that propagate through the passage / channel toward the eardrum.The loudspeaker module works in conjunction with the housing and the thermometer module to define an infrared radiation path and a sound wave path within the passage / channel. These paths are separate from each other, and the infrared radiation from the eardrum and the sound waves generated by the loudspeaker module, respectively, propagate through them. The thermometer module features a tubular optical waveguide positioned within the passage / channel, forming the infrared radiation path. An inner, surrounding surface of the optical waveguide is coated with a layer of gold. The optical waveguide is attached to a radially outer side of the passage / channel. The sound waveguide is funnel-shaped and separate from the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further features and advantages of the present invention will become clear in the following detailed description of the embodiment(s) with reference to the accompanying drawings. It should be noted that various features may not be shown to scale. Fig. Figure 1 is a perspective exploded view of a conventional earplug. Fig. Figure 2 is a perspective exploded view showing an embodiment of an earplug according to the present invention. Fig. Figure 3 is a perspective view of the embodiment, with a section of a front housing of the embodiment omitted. Fig. Figure 4 is a cross-sectional view of a sound waveguide of the embodiment. Fig. Figure 5 is a frequency response diagram illustrating the magnitude of the noise produced by the embodiment. DETAILED DESCRIPTION

[0017] Before the present invention is described in more detail, it should be noted that, where applicable, reference numerals or end sections of reference numerals have been repeated in the figures to indicate corresponding or analogous elements which may optionally have similar properties.

[0018] It should be noted that, according to the present invention, spatially relative terms such as "above", "below", "top", "bottom", "on", "above", "downwards", "upwards", "front", "backwards" and the like may be used when referring to the features illustrated in the drawings. The features may be oriented differently (e.g., rotated by 90 degrees or in other orientations), and the spatially relative terms used here may be interpreted accordingly.

[0019] According to the Fig. 2 and Fig. Figure 3 comprises an embodiment of an earplug according to the present invention, comprising a housing 2, a thermometer module 3, and a loudspeaker module 4. The thermometer module 3 and the loudspeaker module 4 are arranged in the housing 2.

[0020] In this embodiment, the housing 2 comprises a front housing part 21, a rear housing part 22, and a rear cover 23. The front housing part 21 is connected to the rear housing part 22 and has a main section 211 that interacts with the rear housing part 22 to define a cavity 20, and a neck section 212 that extends forward from the main section 211. The neck section 212 tapers away from the main section 211 and includes a passage / channel 213 that is spatially connected to the cavity 20 and has a through-opening 214 located distal to the main section 211. The rear cover 23 is mounted on one side of the rear housing part 22 opposite the front housing part 21.It should be noted that in this embodiment, the housing 2 is physically divided into the front housing part 21, the rear housing part 22, and the rear cover 23, which are connected to one another. In a modification, however, the housing 2 can be physically divided into housing parts that differ from those of the embodiment described above, or it can be formed in one piece using a mold.

[0021] In this embodiment, the thermometer module 3 is configured to receive infrared radiation from the eardrum of a user as a tympanostomy thermometer in order to monitor the user's body temperature. The thermometer module 3 comprises an infrared sensor 31, an optical fiber 32, and an infrared filter 33. The infrared sensor 31 is arranged in the cavity 20.

[0022] The optical waveguide 32 is configured such that it is arranged as a tube within the passage / channel 213. The optical waveguide 32 has an inlet opening located near the passage / channel opening 214, through which the infrared radiation from the eardrum can enter the optical waveguide 32, and an outlet opening located away from the passage / channel opening 214 and covered by the infrared sensor 31. The optical waveguide 32 defines an infrared radiation path within the passage / channel 213, is attached to a radially outer side of the passage / channel 213, and occupies a smaller section of the passage / channel 213. The remaining section of the passage / channel 213 (i.e., a larger section of the passage / channel 213) is separated from the infrared radiation path and serves as an acoustic wave path. The inlet opening of the optical waveguide 32 occupies a smaller section of the passage / channel opening 214.An inner surface of the optical waveguide 32 is gold-plated, thus improving infrared reflection within the optical waveguide 32. The infrared filter 33 covers the inlet opening of the optical waveguide 32 and prevents contaminants from penetrating the infrared radiation path and adhering to the inner, surrounding surface of the optical waveguide 32. In this embodiment, the infrared filter 33 can be made of crystalline silicon or an infrared-transparent polymer, such as high-density polyethylene (HDPE), which exhibits high transparency with respect to a wavelength of 10 micrometers.

[0023] Since the inlet opening of the optical fiber 32 is located next to the through-opening 214 and the outlet opening of the optical fiber 32 is covered by the infrared sensor 31, radiation irrelevant to the eardrum temperature, such as infrared radiation from the neck section 212 of the housing 2, cannot penetrate the optical fiber 32. Therefore, the infrared radiation from the eardrum can be fully received by the infrared sensor 31, allowing the thermometer module 3 to accurately determine the user's body temperature. Because the optical fiber 32 is attached to a radial outer surface of the through-opening / channel 213, the integrity of the sound wave path is maintained.

[0024] The loudspeaker module 4 comprises a loudspeaker 41, a sound waveguide 42, and a sound filter 43. The loudspeaker 41 is arranged in the cavity 20.

[0025] The sound waveguide 42 is essentially arranged in the cavity 20 and extends into the sound wave path. As shown from Fig. As can be seen in Figure 4, the sound waveguide 42 is funnel-shaped and has a conical section 421 and a pipe section 423 connected to the conical section 421. The conical section 421 is located in the cavity 20 and tapers towards the passage / channel 213. The pipe section 423 is arranged at a tapered end of the conical section 421 and extends into the passage / channel 213. The conical section 421 of the sound waveguide 42 defines a conical space within it, which tapers towards the pipe section 423 and serves as a sound collection chamber 422. The sound collection chamber 422 has an inlet opening located distal to the tube section 423 and in a first imaginary plane, and an outlet opening located near the tube section 423 and in a second imaginary plane parallel to the first imaginary plane.Section 423 of the tube defines a sound outlet chamber 424, which is spatially connected to the outlet opening of the sound collection chamber 422. In one embodiment, the diameter of the inlet opening of the sound collection chamber 422 is D1, the diameter of the outlet opening of the sound collection chamber 422 is D2 and is smaller than D1, the distance between the inlet opening and the outlet opening of the sound collection chamber 422 (i.e., the distance between the first imaginary plane and the second imaginary plane) is H, and the length of the tube section 423 of the sound waveguide 42 is A. The diameter of the tube section 423 is equal to the diameter of the outlet opening of the sound collection chamber 422. In a modification, the inlet opening and the outlet opening of the sound collection chamber 422 need not necessarily be circular.The geometric relationship between the inlet opening and the outlet opening of the sound collection chamber 422 can be derived by analogy according to the above.

[0026] In this embodiment, the sound collecting chamber 422 is axially symmetric and symmetric about a central axis (C) that extends through a central portion of the inlet opening of the sound collecting chamber 422 and a central portion of the outlet opening of the sound collecting chamber 422 and is perpendicular to the first imaginary plane and the second imaginary plane. In a modification, the sound collecting chamber 422 can be asymmetric. In particular, when the sound collecting chamber 422 is asymmetric, a central axis extending through a central portion of the inlet opening of the sound collecting chamber 422 and perpendicular to the first imaginary plane does not extend through a central portion of the outlet opening of the sound collecting chamber 422, and the distance between the central portion of the inlet opening and the central portion of the outlet opening in a direction perpendicular to the central axis is less than one-quarter of the diameter of the inlet opening of the sound collecting chamber 422 (D1).

[0027] The loudspeaker 41 is fixed at the inlet opening of the sound collection chamber 422 and has a diameter corresponding to the diameter of the inlet opening (D1). The loudspeaker 41 operates by generating sound waves that pass through the sound waveguide 42 and into the sound wave path. The sound filter 43 covers one end of the sound wave path distal to the sound waveguide 42 (i.e., the sound filter 43 covers a section of the through-opening 214) and prevents contaminants from entering the sound wave path and obstructing the sound waves generated by the loudspeaker 41. In one embodiment, the sound filter 43 can be configured with several miniaturized through-holes through which the sound waves can pass.

[0028] In one embodiment, the earplug further comprises an earpiece 5 which is attached to a distal end of the neck section 212 of the housing 2. In practice, the neck section 212 is inserted into the user's ear canal, and the earpiece 5 conforms tightly to an inner surface surrounding the ear canal. The earpiece 5 is flexible and can be made of a foam material.

[0029] In one embodiment, the earplug further comprises a battery 6, which is arranged in the cavity 20 and is electrically connected to the loudspeaker 41 and / or the infrared sensor 31. In one embodiment, the battery 6 is designed to be rechargeable. In another embodiment, the earplug further comprises a circuit board 7, which is shown in the rear housing part 22 of the housing 2 and is electrically connected to the loudspeaker 41 and / or the infrared sensor 31.

[0030] When a diaphragm of the loudspeaker 41 vibrates, air particles on a diaphragm surface are set into vibration. After the air particles have acquired an initial velocity and kinetic energy from the diaphragm, they initiate a multidirectional sound propagation process in the cavity 20. If an obstacle is located in the path along which the air particles move, the sound quality of the earbud is impaired by reflection, interference, and reverberation of the sound waves propagating along the path. The funnel-shaped sound waveguide 42 according to the present invention eliminates these factors that reduce sound quality.

[0031] The funnel-shaped sound waveguide 42 improves the sound quality in three ways. Regarding the first aspect, the tapered sound collection chamber 422 of the sound waveguide 42 helps the sound waves radiating from the loudspeaker in several directions to propagate towards the sound output chamber 424 and reach the eardrum without encountering an obstacle. Therefore, the sound waves are not distorted by other components in the cavity 20. Regarding the second aspect, this funnel-shaped design of the sound waveguide 42 limits the flow of the sound waves and prevents energy dissipation caused by scattering, thus increasing the total kinetic energy of the emitted sound waves. According to the principles of acoustics, an increase in the kinetic energy of the sound flow leads to an increase in the sound pressure level.Regarding the third aspect, the tapered sound collection chamber 422 of the sound waveguide 42 increases the sound flow velocity of the vibrating air particles in the sound output chamber 424. Thus, when the sound waves generated by the loudspeaker 41 flow through the tapered sound collection chamber 422 of the sound waveguide 42 and exit the sound waveguide 42 via the sound output chamber 424, the velocity of the air particles at an outlet opening of the sound output chamber 424 located away from the sound collection chamber 422 is significantly greater than the initial velocity of the air particles at the diaphragm of the loudspeaker 41 due to the reduced cross-sectional diameter. This increase in air flow velocity at the outlet opening of the funnel-shaped sound waveguide 42 therefore increases the sound pressure level in an audible frequency range.In a low-frequency range, increasing the flow velocity would significantly increase the harmonic amplitude of the air particles' vibrations. According to the principles of acoustics, the sound pressure level is proportional to the vibration amplitude. Therefore, the increase in the sound pressure level in the low-frequency range is more pronounced due to the presence of the sound waveguide 42. Regarding the characteristics of the sound pressure level in the low-frequency range, in a conventional earplug, low-velocity air particles, induced by a small vibration amplitude, generate a low sound pressure level measured near the diaphragm of the conventional earplug's loudspeaker. When the loudspeaker radiates sound waves into an open space, the sound pressure level in the low-frequency range can even decrease.In the earplug according to the present invention, the narrowing sound collection chamber 422 significantly increases the velocity of the air particles flowing through the funnel-shaped sound waveguide 42. In contrast, the same increase in the velocity of the air particles in the high-frequency range contributes only a slight increase in the vibration amplitude, resulting in a slight increase in the sound pressure level. The increase in the sound pressure level is significantly higher in the low-frequency range than in the high-frequency range.

[0032] To verify the feasibility of the earplug according to the present invention, a series of sound pressure level tests were carried out under test conditions according to the international standard IEC 60268-7. In the tests, the sound pressure levels resulting from various sound wave guide devices (e.g., the funnel-shaped sound wave guide 42 of the present invention) were measured. Fig.Figure 5 shows three sound pressure level curves for comparison, where: Curve 1 is represented by a dashed line, Curve 2 by a thin solid line, and Curve 3 by a thick solid line. The sound wave guide for Curve 1, which is commercially used by a well-known headphone company, is a circular plate with a thickness of 1 millimeter and a diameter of 10 millimeters, formed with a centrally located circular hole with a diameter of 2.5 millimeters. The distance between the circular plate and a loudspeaker diaphragm interacting with the sound wave guide for Curve 1 is 1.5 millimeters. The sound wave guide for Curve 2 is the funnel-shaped sound wave guide 42 of the present invention with the following specific parameters: D1 = 10 millimeters, D2 = 2.5 millimeters, H = 3.0 millimeters, and A = 4.0 millimeters.The sound-guiding device for curve 3 is the funnel-shaped sound waveguide 42 according to the present invention with the following specific parameters: D1 = 10 mm, D2 = 2.0 mm, H = 3.0 mm, and A = 2.5 mm. A comparison of the three sound pressure level curves shows that the two funnel-shaped sound waveguides 42 of the present invention are capable of generating higher sound pressure levels in the audible frequency range. The difference between curves 2 and 3 shows that the geometric parameters can significantly influence the performance of the funnel-shaped sound waveguides 42. To achieve good performance of the sound waveguides 42 according to the present invention, it is proposed that the values ​​of the geometric parameters be selected from the following intervals: 0.15 <D2D1<0,35;0,12<HD1<0,5; and 0.10 <AD1<0,6;

[0033] In summary, the earplug according to the invention forms an infrared radiation path and a sound wave path that are separated from each other and through which the infrared radiation and sound waves, respectively, can pass. Thus, the thermometer module 3 can accurately determine the user's body temperature without impairing the sound quality of the earplug. Since the inner surface of the optical waveguide 32 is coated with a layer of gold, the infrared reflection within the optical waveguide 32 is improved, thereby increasing the accuracy of the thermometer module 3. Furthermore, the funnel-shaped sound waveguide 42 shapes the sound pressure level of the earplug according to the invention in such a way that it is significantly higher in the low frequency range.

[0034] In the above description, numerous specific details have been set forth for explanatory purposes, in order to provide a thorough understanding of the embodiment(s). However, it will be clear to a person skilled in the art that one or more other embodiments may also be carried out without some of these specific details. It should also be recognized that the reference in this description to "(the) embodiment," "(any) embodiment," an embodiment with an ordinal number, and the like means that a particular feature, structure, or property may be included in the practice of the present invention. It should further be noted that in the description, various features are sometimes referred to in a single embodiment, Fig.or whose description may be grouped to simplify the present invention and facilitate understanding of various inventive aspects; this does not mean that each of these features must be combined with the presence of all the other features. In other words, if in one of the described embodiments the embodiment of one or more features or specific details does not impair the embodiment of one or more other features or specific details, one or more features may be selected and implemented alone without the other features or specific details. It should also be noted that, where applicable, one or more features or specific details from one embodiment may be implemented together with one or more features or specific details from another embodiment in practice.

[0035] While the present inventions have been described in connection with the exemplary embodiment(s), this disclosure is not limited to the specified embodiment(s) but is intended to cover various arrangements included in the sense and scope of the broadest interpretation, such that all such modifications and equivalent arrangements are covered.

Claims

[1] An earplug designed to be inserted into a user’s ear canal, comprising: a housing (2) forming a cavity (20) and a passage (213) therein, the passage (213) being in spatial communication with the cavity (20) and having a through opening (214) remote from the cavity (20) and in spatial communication with the auditory canal; a thermometer module (3) provided in the housing (2) and configured to receive infrared radiation from a user's eardrum via the passage / channel (213) to determine a user's body temperature; and a loudspeaker module (4) arranged in the housing (2) and designed to generate sound waves that propagate through the passage / channel (213) in the direction of the eardrum, wherein the loudspeaker module (4) cooperates with the housing (2) and the thermometer module (3) to form an infrared radiation path and a sound wave path within the passage / channel (213) that are separated from each other and through which the infrared radiation from the eardrum and the sound waves generated by the loudspeaker module (4) respectively propagate; wherein the thermometer module (3) comprises a tubular optical waveguide (32) arranged in the passage / channel (213) and forming the infrared radiation path therein, an inner surrounding surface of the optical waveguide (32) being coated with a layer of gold; wherein the optical fiber (32) is attached to a radially outer side of the passage / channel (213); wherein the sound waveguide (42) is funnel-shaped and is different from the housing (2). [2] The earplug of claim 1, wherein the optical waveguide (32) occupies a smaller portion of the passage / channel (213) and a larger portion of the passage / channel (213) serves as the sound wave path. [3] The earplug of claim 1, wherein the optical fiber (32) has an inlet opening that occupies a smaller portion of the through-hole (214) and that allows infrared radiation from the eardrum to enter the optical fiber (32), and an outlet opening located distal to the through-hole (214); wherein the thermometer module (3) further comprises an infrared filter (33) and the tubular optical fiber (32), the infrared filter (33) covering the inlet opening of the optical fiber (32) and being made of either crystalline silicone or an infrared-transparent polymer. [4] Earplug according to claim 1, wherein the loudspeaker module (4) comprises a loudspeaker (41) and a sound waveguide (42), wherein the loudspeaker (41) is arranged in the cavity (20), wherein the sound waveguide (42) is arranged substantially in the cavity (20) and extends into the sound wave path, which has a cone section (421) and a tube section (423) connected to the cone section (421), wherein the cone section (421) is arranged in the cavity (20) and tapers towards the passage / channel (213), wherein the tube section (423) is connected to a tapered end of the cone section (421) and extends into the passage / channel (213). [5] The earplug according to claim 4, wherein the conical portion (421) of the acoustic waveguide (42) forms a sound collection chamber (422) that tapers toward the tube portion (423), the sound collection chamber (422) having an inlet opening disposed distally from the tube portion (423) and located in a first imaginary plane, and an outlet opening disposed proximate the tube portion (423) and in a second imaginary plane parallel to the first imaginary plane, the inlet opening and the outlet opening of the sound collection chamber (422) being circular, and a diameter of the outlet opening of the sound collection chamber (422) being smaller than that of the inlet opening.

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