Abstract: Disclosed are a closed loudspeaker box, a display device including the closed loudspeaker box, and a method for testing the closed loudspeaker box. The closed loudspeaker box includes: a housing; a chamber surrounded by the housing; a through hole penetrating the housing and communicating with the chamber; and a plug, at least a part of the plug is inserted into the through hole, wherein the plug includes a plug main body and a vent hole penetrating the plug main body, and the vent hole communicates the chamber and a space outside the housing.

Abstract: The present invention relates to a bone conduction speaker and its compound vibration device. The compound vibration device comprises a vibration conductive plate and a vibration board, the vibration conductive plate is set to be the first torus, where at least two first rods inside it converge to its center; the vibration board is set as the second torus, where at least two second rods inside it converge to its center. The vibration conductive plate is fixed with the vibration board; the first torus is fixed on a magnetic system, and the second torus comprises a fixed voice coil, which is driven by the magnetic system. The bone conduction speaker in the present invention and its compound vibration device adopt the fixed vibration conductive plate and vibration board, making the technique simpler with a lower cost; because the two adjustable parts in the compound vibration device can adjust both low frequency and high frequency area, the frequency response obtained is flatter and the sound is broader.

Abstract: The present invention relates to a bone conduction speaker and its compound vibration device. The compound vibration device comprises a vibration conductive plate and a vibration board, the vibration conductive plate is set to be the first torus, where at least two first rods inside it converge to its center; the vibration board is set as the second torus, where at least two second rods inside it converge to its center. The vibration conductive plate is fixed with the vibration board; the first torus is fixed on a magnetic system, and the second torus comprises a fixed voice coil, which is driven by the magnetic system. The bone conduction speaker in the present invention and its compound vibration device adopt the fixed vibration conductive plate and vibration board, making the technique simpler with a lower cost; because the two adjustable parts in the compound vibration device can adjust both low frequency and high frequency area, the frequency response obtained is flatter and the sound is broader.

Abstract: A system and method for a hybrid ring-radiator headphone driver, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

Abstract: An earbud comprises: a casing in which a sound cavity is provided; a speaker disposed in the sound cavity and dividing the sound cavity into a front sound cavity and a rear sound cavity; and an acoustic structure located in the rear sound cavity. The acoustic structure comprises a first sound guiding wall and a cover plate, the first sound guiding wall is attached to a bottom surface of the rear sound cavity and is configured to, together with at least a part of an inner wall of the casing, constitutes a sound guiding groove, and the cover plate is mounted at an upper opening part of the sound guiding groove, such that the sound guiding groove forms a bass pipe which communicates from the rear sound cavity to at least one aperture of the casing.

Abstract: An electro-acoustic transducer with a diaphragm with a front side and a rear side, the diaphragm configured to radiate front side acoustic radiation from its front side and rear side acoustic radiation from its rear side. There is a magnet, and a magnetic circuit that defines a path for magnetic flux of the magnet and comprises a gap, wherein the magnetic circuit comprises a pole piece. A voice coil is located in the magnetic circuit gap and configured to move the diaphragm. A basket is supported by the magnetic circuit. The basket supports the diaphragm. There are first and second openings in the basket. The first and second basket openings are both configured to receive one of the front side acoustic radiation and rear side acoustic radiation. The first opening is spaced from the second opening. The first opening has a greater acoustic resistance than the second opening.

Abstract: The present invention provides a headphone structure for extending and enhancing resonance comprising a main body, a cover and a shield. The main body has an accommodating portion for accommodating a speaker, a plurality of master sound guiding holes are penetrated in the accommodating portion and a plurality of side sound guiding holes are penetrated in the main body. A rear cavity space is formed between the cover and the main body, and the shield forms a rear cavity extending space to communicate with the side sound guiding holes and the rear cavity space. Thereby, the headphone structure can reduce air damping through the rear cavity extending space communicating with the rear cavity space, so as to achieve effects of increasing stroke displacement of the speaker and reducing air suppression of sound.

Abstract: Methods and systems are provided for an awareness intelligence headphone with an always listening mode. Headphone units share the ability to output audio sound to a user, but may not provide additional functionality that users may require. A headphone unit with the always listening mode is used to analyze ambient noise surrounding the headphone unit in order to detect predetermined sounds, issue alerts to a user, and respond to an input command from the user.

Abstract: A headphone having a pair of housings including speaker units, an ear accommodating portion having a frame surrounding an ear and in contact with a head part and a connection portion connecting the frame and the housing, covering the ear, and providing ventilation to the ear, and an arm connecting the pair of housings to each other.

Abstract: A system and method are provided for improving speech recognition accuracy. Contextual information about user speech may be received, and then speech recognition analysis can be performed on the user speech using the contextual information. This allows the system and method to improve accuracy when performing tasks like searching and navigating using speech recognition.

Abstract: A headset cup having a front cavity and a rear cavity separated by a driver, with a mass port tube connected to the rear port to present a reactive acoustic impedance to the rear cavity, in parallel with a resistive port, the total acoustic response of the rear cavity remaining linear at high power levels. In some embodiments, the mass port tube is made of metal, while the headset cup is otherwise made of plastic.

Abstract: A personal audio equipment provided with an air vent unit and a noise cancellation function, comprising: a sound reproduction unit in a form modified to have an air vent unit that may partly open an ear canal; a speaker cover unit; the air vent unit; a noise cancellation unit; and a sound wave sensor. Due to having the air vent unit penetrating the center of the audio equipment, the personal audio equipment provided with an air vent unit and a noise cancellation function is capable of discharging moisture, easily sensing outside sounds when not in use, effectively blocking the outside sounds by automatically operating the noise cancellation function during a phone conversation, and sensing sound waves, such as alert or horn sounds that require a user's attention, to thereby block the noise cancellation function when necessary.

Abstract: Disclosed is an earphone comprising a loudspeaker unit, an audio signal wire electrically connected to the loudspeaker unit, and an auxiliary structure; the auxiliary structure comprises a front cover and a housing; a front acoustic cavity is defined as a space between the front cover and the loudspeaker unit, and a rear acoustic cavity is defined as a space between the housing and the loudspeaker unit; an acoustic guide channel capable of enhancing low-frequency performance of the earphone is disposed on one side of an inner sidewall of the housing closer to the loudspeaker unit; the acoustic guide channel comprises an open end and a closed end, and a bottom wall of the acoustic guide channel is provided with a plurality of through holes at a position closer to the closed end. An earphone with this structure improves low-frequency and middle-frequency sound effects of products, and makes the earphone have a good appearance.

Abstract: A tunable earphone is provided. By moving a tuning rod inserted into a hollow shell with a varied depth to drive a tuning plate thus changing the distance between a speaker and the tuning plate, the air in the hollow shell can resonate for different volumes and different path lengths, thereby adjusting a frequency response characteristic of the whole earphone.

Abstract: A headset apparatus including a speaker housing having an acoustic impedance and configured for conversion between a first listening mode and a second listening mode by rotation of the at least one speaker housing about an axle. The headset apparatus includes at least one vent configured to alter the acoustic impedance of the at least one speaker housing. The headset apparatus also includes a valve configured to open the at least one vent in the first listening mode and configured to close at least some portion of the at least one vent in the second listening mode.

Abstract: An earphone is disclosed. The earphone includes a housing forming a volume, a plurality of sound holes arranged in the housing, a sound generator received in the volume of the housing and cooperatively with the housing forming a front volume, a supporter accommodated in the volume of the housing and engaging with the sound generator forming a main back volume, and cooperatively with the housing forming a auxiliary back volume. The supporter includes bottom, a sidewall upwardly extending from the bottom and an acoustic pipe, the acoustic pipe communicating the main back volume with the auxiliary back volume for balancing an internal acoustic pressure of the earphone.

Abstract: The present invention relates to earphone arrangements configured to accommodate an acoustically-resistant couple within the compact dimensions of ear-bud type earphones, and aims to incorporate a front volume to rear volume acoustic couple into an earphone without requiring significant addition to the lateral dimensions of the earphone. The earphone has an elongate sound outlet port that locates into a listener's ear canal and bears an internal support surface which is apertured and communicates with the outlet port. A microspeaker is supported on the support surface and projects sound through the aperture and toward the outlet port. Furthermore, the housing includes a front cavity in front of the microspeaker and in communication with the outlet port, and a rear cavity behind the microspeaker. The support surface bears a recess that communicates with the front cavity, and an acoustic resistor is accommodated in the recess.

Abstract: An earphone includes a first acoustic chamber with one or more of a reactive element and a resistive element for acoustically coupling the first acoustic chamber with an environment external to the earphone. The earphone includes an acoustic transducer and a second acoustic chamber separated from the first acoustic chamber by the acoustic transducer. A housing supports the earphone from the concha of a wearer's ear and extends the second acoustic chamber at least to an entrance of an ear canal of the wearer's ear. A port acoustically couples the first and second acoustic chambers.

Abstract: A headphone for reproducing sound stage effect comprises of a housing including outer surface covering the ear, an inner wall corresponding to the combination of the outer surface, and a hollow chamber arranged inside the housing, a sound guiding hole is disposed in the center of the inner wall guiding the sound output; a padding, one side is combined with an outside of the inner wall, the other is for contacting with human face and a pinhole is arranged in the center corresponding to the sound guiding hole; a speaker baffle is arranged at one side of the chamber of the housing provided with an open hole, which the front is faced with the other side and integrated tightly with the outer surface and the inner wall without covering the sound guiding hole, and which is set close to the vertical with the inner wall to form a small space for accommodating a speaker; the speaker is disposed behind the baffle, which sounds export to the chamber by the open hole of the baffle.

Abstract: An earphone including a housing, a speaker, a tuning mechanism and an acoustic damper is provided. The housing has a sound-output opening. The speaker is disposed at the sound-output opening. The speaker and the housing together define a compartment. The speaker has an inner chamber and a through hole for communicating the inner chamber and the compartment. The tuning mechanism is movably disposed at the housing and extended into the compartment. The acoustic damper is disposed between the tuning mechanism and the speaker, and located at the through hole. The tuning mechanism is configured to move to compress or release the acoustic damper for adjusting the air permeability of the acoustic damper.

Abstract: An earpiece is disclosed. The earpiece includes a housing forming a volume therein, a number of sound holes arranged in the front end and rear end of the housing, a sound generator accommodated in the volume, an ear gel attached to a front end of the housing, a wire electrically connected to the sound generator, wherein a adjusting module is assembled to the housing, a plurality of front vents are disposed on the front end of the housing, and the amount of the front vents communicating with the volume is mechanically altered by the adjusting module.

Abstract: An earphone including a housing, a speaker, a plurality of porous materials and a tuning mechanism is provided. The housing has a containing space, a sound-output opening and a plurality of tuning holes, wherein the containing space communicates with outside of the housing through the tuning holes. Areas of the tuning holes are substantially the same. The speaker is disposed at the sound-output opening and located in the containing space. The air permeability of each porous material are different, and the porous materials cover the tuning holes correspondingly. The tuning mechanism is disposed at the housing and shields at least one of the tuning holes selectively.

Abstract: A fitting provided for earbud-type personal audio speakers may be formed as a homogeneous, integral component molded from an elastomeric polymer, such as silicone, urethane, or other elastomeric resins. A sleeve fitted to the speaker engages the fitting to the speaker, while ribs extending from the sleeve terminate in flutes conformal to an ear canal of a user. Axial insertion of the fitting and speaker into an ear of a user results in localized deflection of flutes and ribs in order to accommodate size and shape of an ear canal, resulting in transmission of sound from the speaker directly through the sleeve into an ear canal of a user, while also permitting environmental sounds to pass along a parallel path over the outside of the sleeve, between the ribs.

Abstract: A tunable earphone includes a speaker for making sound, a shell receiving the speaker and defining a resonance cavity therein, and a tunable element rotatably and removably mounted on the shell. The shell has a top thereof recessed downward to form a receiving cavity. A supporting plate is formed at a bottom of the receiving cavity. A damping vent is opened in the supporting plate to connect the resonance cavity with the receiving cavity. The tunable element defines a through hole passing therethrough and aligned with the damping vent of the shell. A damping plate is integrally molded on a bottom of the tunable element. The damping plate is located in the receiving cavity and against the supporting plate to separate between the damping vent and the through hole for smoothening the frequency response of the sound pressure level in the resonance cavity while the speaker making sound.

Abstract: A tunable earphone includes a body, a front cavity, a rear cavity and a decorating plat. The body includes a small air hole and a large air hole. The front cavity and the rear cavity are respectively disposed on the body. The decorating plate covers the rear cavity and includes a receiving groove, a shielding member and a channel. The shielding member and the channel are disposed in the receiving groove. When the decorating plate is rotated to a first position, the shielding member shields the large air hole, the channel corresponds to the small air hole, so that the front cavity communicates with the rear cavity through the channel. When the decorating plate is rotated to a second position, the shielding member shields the small air hole, the channel corresponds to the large air hole, so that the front cavity communicates with the rear cavity through the channel.

Abstract: Provided is an earphone with an open-close type enclosure in which it is possible to open or close the communicating hole of the enclosure so as to reinforce the high-pitched tones or low-pitched tones of the sound being listened to. The earphone includes a sound wave generation means 150 that generates sound waves depending on electric signals, a body 100 including an enclosure which encloses the back of the sound wave generation means, and a worn portion 200 in which a sound wave path for transmitting a sound wave to the external auditory canal is formed, and which is worn in the external auditory canal.

Abstract: An earphone with tension diaphragm includes a front portion, a rear portion, a silicone gel earplug, a filtering net and a sound generating unit. As a user pushes the earphone into his ear, the diaphragm of the sound generating unit has a deformation and thus an air turbulence would be generated. This air turbulence would then cause a deformation of the tension diaphragm and this deformation would in turn eliminate the strange and unpleasant noises generated as a user pushes an earphone into his ear. Therefore, better audio signals may be achieved and a better low-frequency effect may be reached. Also, because the earphone of the present invention is water-resistant, it may be used under water. In addition, other water-resistant earphones on the market do not have such tension diaphragm.

Abstract: An earmuff which is adapted to covering a driver includes a first case having a first through hole and a second case having a second through hole. The second case accommodated within the first case to form an inner chamber where the driver is disposed therein. Since air flows between the first case and the second case via the first through hole and the second through hole, a satisfactory ventilation effect can be achieved and thus feeling of being at ease can be furnished.

Abstract: Hearing protection devices are disclosed. One hearing protection device includes a first material, having sound attenuating characteristics, shaped to cover over an ear of a user; at least one aperture formed in the first material; and a second material positioned over the aperture.

Abstract: A mountable multi-directional audio device comprises at least one broadcasting device, which has a sounding portion outwardly; and at least one connecting member, the any end of the connecting member is connected with the broadcasting device.

Abstract: A portable headset for equalizing air pressure across the tympanic membrane of a user's ears. The device comprises two earpieces secured at opposing ends of a headband. The earpieces are cup-shaped housings containing a fan and a speaker. A mesh screen covers the open portion of the housing to protect the user's ear from contact with the fan blades. Additionally, a cushion is disposed along the perimeter of the housing to buffer the user's ear from the device. When the device is turned on, the fans rotate and air is pushed into or pulled out of the ear canals. Rate of rotation and direction of rotation are controlled via at least one pressurization selection dial. Thus the air pressure can be changed as a plane ascends or descends through the atmosphere.

Abstract: An earmuff and a headphone includes: a headband; an ear cup attached to the headband; a baffle board fixed on the ear cup; an ear pad engaged to the baffle board. An air-permeable member provided between the baffle board and the ear pad.

Abstract: An earphone includes a front housing, a tuning element, a rear housing and a loudspeaker. The front housing has a hollow sound tube, a sealed cover and a sealed barrel. The sealed cover defines a tuning hole. The sealed barrel defines a leaking hole connecting between the tuning hole and an external space of the earphone. The tuning element rotatably mounted to the front housing has a tuning pillar inserted in the tuning hole. The tuning pillar defines a tuning fillister. The rear housing is assembled forward to the front housing for locating the loudspeaker between the front housing and the rear housing. A sound cavity is formed among the front housing, the rear housing and the loudspeaker, and is communicated with the tuning fillister. A relative position of the tuning fillister and the leaking hole is capable of being modulated by means of rotating the tuning element.

Abstract: An arrangement includes a circuit carrier and a housed microphone. A mounting side of the housed microphone is mounted on a top side of the circuit carrier. The housed microphone includes solderable contacts on the mounting side and a sound entry opening facing the circuit carrier. An acoustic channel connects the sound entry opening and surroundings above the circuit carrier.

Abstract: A headphone having a waveguider is disclosed which can control the amount of air flowing into the headphone. The headphone includes: a housing having a receiving space therein and at least one or more air inlets at one side thereof, in which the housing is opened at the front side thereof a speaker placed in the receiving space, for generating audio sounds according to input electrical signals; a cover for closing the front side of the housing, the cover forming a plurality of audio sound through-holes through which the audio sounds from the speaker pass; and a waveguider slidably and rotatably installed to the housing. The waveguider includes a kernel part protrudently formed, for guiding the audio sounds passing through the cover to the inner ear, and an opening/closing part for closing at least one or more air inlets according to a rotation angle thereof to control the amount of air that instantly flows into the housing.

Abstract: A fitting provided for earbud-type personal audio speakers may be formed as a homogeneous, integral component molded from an elastomeric polymer, such as silicone, urethane, or other elastomeric resins. A sleeve fitted to the speaker engages the fitting to the speaker, while ribs extending from the sleeve terminate in flutes conformal to an ear canal of a user. Axial insertion of the fitting and speaker into an ear of a user results in localized deflection of flutes and ribs in order to accommodate size and shape of an ear canal, resulting in transmission of sound from the speaker directly through the sleeve into an ear canal of a user, while also permitting environmental sounds to pass along a parallel path over the outside of the sleeve, between the ribs.

Abstract: An earphone device with a function of sound quality regulation is provided. The earphone includes a housing, a cover, a speaker and a regulating device. The housing has an accommodating space for receiving the speaker and a plurality of regulating holes for connecting the accommodating space to the outside. One end of the regulating device is fixed on the cover. A blocking portion, which is disposed on the other end of the regulating device and extends into the accommodating space, can partially or completely block the regulating holes when the cover is turned, thereby regulating the leakage between the accommodating space and the outside to achieve different output sound quality.

Abstract: A headphone having a headband and two acoustic transducers disposed at two ends of the headband is disclosed. Each acoustic transducer includes a baffle plate installed with a speaker, a spacer, a vent and an acoustic modulator. The baffle plate and speaker divide the acoustic transducer into a front and a back chamber. The front chamber is configured for communicating with a user's ear. The spacer is disposed behind the speaker to divide the back chamber into a first back chamber and a second back communicated with each other. The vent is disposed in a back wall of the acoustic transducer to communicate the first back chamber with outside. The first acoustic modulator is disposed between the front and second back chambers. The headphone modulates resonance frequency at low frequency bands through the acoustic modulator.

Abstract: An earmuff which is adapted to covering a driver includes a first case having a first through hole and a second case having a second through hole. The second case accommodated within the first case to form an inner chamber where the driver is disposed therein. Since air flows between the first case and the second case via the first through hole and the second through hole, a satisfactory ventilation effect can be achieved and thus feeling of being at ease can be furnished.

Abstract: A headphone having a headband and two acoustic transducers disposed at two ends of the headband is disclosed. Each acoustic transducer includes a baffle plate installed with a speaker, a spacer, a vent and an acoustic modulator. The baffle plate and speaker divide the acoustic transducer into a front and a back chamber. The front chamber is configured for communicating with a user's ear. The spacer is disposed behind the speaker to divide the back chamber into a first back chamber and a second back communicated with each other. The vent is disposed in a back wall of the acoustic transducer to communicate the first back chamber with outside. The first acoustic modulator is disposed between the front and second back chambers. The headphone modulates resonance frequency at low frequency bands through the acoustic modulator.

Abstract: Provided is an adjustable audio headphone, including a headphone body, a damping object and a pressing mechanism. The headphone body includes a headphone shell, which forms a sound cavity in inside thereof and a receiving chamber on one end thereof. A bottom surface of the receiving chamber forms a through hole communicated with the sound cavity. The damping object is made of compressible material such as sponge, elastic plastic, textile and so on and. The damping object is placed into the receiving chamber of the headphone shell. The pressing mechanism is mounted on the headphone shell and is capable of pressing the damping object. The adjustable audio headphone of the present invention can compress the damping object to change the density of the damping object by employing the pressing mechanism, thereby varying the pressure of the sound cavity and realizing the object of adjusting the audio thereof.

Abstract: The present invention relates to earphone arrangements configured to accommodate an acoustically-resistant couple within the compact dimensions of ear-bud type earphones, and aims to incorporate a front volume to rear volume acoustic couple into an earphone without requiring significant addition to the lateral dimensions of the earphone. The earphone has an elongate sound outlet port that locates into a listener's ear canal and bears an internal support surface which is apertured and communicates with the outlet port. A microspeaker is supported on the support surface and projects sound through the aperture and toward the outlet port. Furthermore, the housing includes a front cavity in front of the microspeaker and in communication with the outlet port, and a rear cavity behind the microspeaker. The support surface bears a recess that communicates with the front cavity, and an acoustic resistor is accommodated in the recess.

Abstract: An inserting type earphone device is broken down into a signal-to-sound converter, an ear pad to be inserted into an acoustic meatus of user, a sound tube provided between the signal-to-sound converter and the ear pad and a switching mechanism provided in association with the sound tube and ear pad, and a sound hole, which is formed in the sound tube for connecting a sound propagation hole to the outside, is open to and closed with the switching mechanism; the switching mechanism makes the sound hole open and closed through rotation thereof around the sound tube so that the ear pad is not inclined in the acoustic meatus during the rotation, whereby the ear pad is not dropped off from the acoustic meatus.

Abstract: An earphone comprising a moving part, adapted to close an auditory port thereby toggling the earphone from an open mode allowing environmental sounds to reach an ear of the user to a closed mode blocking the ear of the user. The closing is accomplished while the earphone is in operation. The sound capsule of the earphone may also be activated and deactivated according to the mode of the earphone.

Abstract: An ear pad includes an exterior body which is mounted on a headphone and is formed in a ring shape having a hollow internal space, at least a contact surface of the exterior body with a user's temporal region having air permeability when the headphone is worn; and air permeable members placed in the exterior body.

Abstract: An earphone which fits into an ear is disclosed. The earphone includes an electroacoustic transducer for converting an audio signal into sound and a housing for holding the electroacoustic transducer. The housing includes a sound output unit for introducing the sound produced by the electroacoustic transducer into the ear canal of an ear when the housing is placed in the ear. The electroacoustic transducer is oriented so that it the sound in a direction which is transverse to the ear canal of the ear.

Abstract: A method of providing an audio signal to a headphone apparatus for a user is disclosed. The method comprises providing a headphone apparatus comprising at least one left speaker for a left ear of a user having a sound path from the left speaker to the left ear canal and at least one right speaker for a right ear of the user having a sound path from the right speaker to the right ear canal, wherein the sound path of the left speaker has a different length from the sound path of the right speaker. The method further comprises sending an audio signal simultaneously to the left speaker and right speaker thereby creating a timing difference in the time the signal is received by each ear canal based on the difference is the length of the sound path.

Abstract: The invention relates to a headset comprising at least one earphone and a headset microphone for registering voice signals of the headset wearer. The headset microphone is fixed to one of the earphones. The earphone comprises at least one electroacoustic transducer, a rear volume, and a front volume which lies in front of the electroacoustic transducer. A first channel runs from the exterior through the earphone to the front volume. In addition, at least one acoustic filter and/or a microphone is arranged inside the first channel, in which a mechanical filter which protects against dirt and/or moisture is also disposed.

Abstract: A headset has a hollow housing having a front wall with at least one sound hole formed thereon, and a rear wall facing the front wall having a plurality of air holes formed thereon. A loudspeaker unit is disposed in the housing and adjacent to the sound hole. An adjustive component is rotatably mounted to the rear wall of the housing. The adjustive component has an adjustive switch outside the rear wall and a blocking slice against an inner surface of the rear wall and connected with the adjustive switch. The adjustive switch is capable of controlling the blocking slice to swing and halt repetitiously, for altering the number of the covered air holes when the adjustive switch is driven to rotate.

Abstract: An insert earphone device includes an electro-acoustic device, an inserting body, a sound tube connected between the electro-acoustic device and the inserting body and an active valve unit provided on the sound tube, the sound tube is formed with a sound propagation path open at both ends thereof to the electro-acoustic device and the inserting body and an external sound entrance open at both end thereof to environment and the sound propagation path, and the active valve unit is formed of electroactive polymer and responsive to voltage supplied through a cable so as to close and open the external sound entrance; when a user wishes to hear external sound, the user changes the polarity of voltage so that the active valve unit is deformed for conducting the environment to the sound propagation path, whereby the user hears the external sound without removing the earphone device from the ear.