Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
  • H04R1/1041—Mechanical or electronic switches, or control elements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
  • H04R1/1091—Details not provided for in groups H04R1/1008 - H04R1/1083
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
  • H04R1/1083—Reduction of ambient noise
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R2460/00—Details of hearing devices, i.e. of ear- or headphones covered by H04R1/10 or H04R5/033 but not provided for in any of their subgroups, or of hearing aids covered by H04R25/00 but not provided for in any of its subgroups
  • H04R2460/11—Aspects relating to vents, e.g. shape, orientation, acoustic properties in ear tips of hearing devices to prevent occlusion

Definitions

• the present invention relates to an audio listening device and a method of audio playback.
• One way to attenuate external noise levels is to use an ear plug for partially or wholly sealing the ear channel from the environment. Sealing of the ears may be advantageous e.g. for the proper use of modern so called balanced armature receivers, which may deliver a hi-fi performance for the user. However, continuous sealing of the ear may not be desired, e.g. in different acoustic environments.
• loudspeaker in particular, an earplug is disclosed with which, when he is not listening to music, the user can observe the ambient sounds without having to remove the earplug from his ear.
• various means are suitable for transmitting the ambient sound to the ear canal of the user, e.g. by electronic transmission, though preferably by an adjustable acoustic valve.
• an audio listening device comprising a housing, shaped to substantially form a pressure seal between an auditory canal of an ear and an external surroundings.
• the housing comprises a pressure relay, a pressure valve, an acoustic generator, and a valve control.
• the pressure relay channel extends through the housing between the auditory canal and the external surroundings.
• the pressure relay channel is arranged for relaying a pressure difference between the auditory canal and the external surroundings.
• the pressure valve is arranged in the pressure relay channel and arranged for switching between an open or closed position for allowing or preventing, respectively, an exchange of pressure between the auditory canal and the external
• the acoustic generator is arranged between the pressure valve and the auditory canal and arranged for generating an acoustic signal into the auditory canal.
• the valve control comprises an actuator, control logic and a pressure sensor.
• the actuator is arranged for switching the valve between the open and closed positions.
• the control logic is arranged for controlling the actuator.
• the pressure sensor is arranged for measuring an internal pressure level in the auditory canal.
• the control logic is arranged for controlling the actuator to switch the pressure valve to an open position when the measured internal pressure level is above a threshold pressure level.
• the measured internal pressure level includes sound pressure caused by the acoustic generator.
• a pressure sensor for measuring the internal pressure in the auditory canal and opening the pressure valve when the measured internal pressure exceeds a pressure threshold, e.g. caused by the acoustic generator, damage and/or discomfort due to over- or under pressure in the ear canal can be prevented.
• the currently proposed audio listening device comprises an internal pressure sensor and control logic that is arranged to open the acoustic valve in response to a measured internal pressure level in the ear canal. While conventional ear plugs are used to seal the ear against external noise levels, the currently proposed audio listening device provides protection against excessive internal pressure levels.
• the ear drum separates the auditory canal of the outer ear (external acoustic meatus) from the middle ear (tympanic cavity). While the middle ear may have a pressure equal to that of the external surroundings by passing air via the Eustachian tubes, the inventors recognized that the pressure in the outer ear may no longer be equihbrated with the external surroundings when the ear is sealed, e.g. by a conventional audio listening device. As a result, a pressure difference between the outer ear and the middle ear may cause a net pressure on the ear drum that may be uncomfortable or damaging to a user of such an audio listening device.
• the pressure sensor is further arranged for measuring an external pressure level of the external
• the control logic is arranged for controlling the actuator to open the pressure valve when a pressure difference between the internal and external pressure levels is higher than a threshold pressure difference.
• the opening of the pressure valve may also be advantageous for equalizing the pressure between the outer and middle ear in environments with varying pressures, e.g. in airplanes or scuba diving. It is currently recognized that in such varying pressure environments, an uncomfortable and potentially damaging pressure difference may occur between the inner and outer ear when the outer ear is sealed from the external surroundings.
• the currently proposed audio listening device may thus be advantageous e.g. for users wishing to listen to audio while traveling by airplane.
• the currently proposed audio listening device may attenuate the ambient noise, e.g. from the airplane, and may equilibrate excess pressure differences, e.g. caused by pressure differences during landing and take-off.
• a method for controlling an audio listening device comprising a housing, shaped to substantially form a pressure seal between an auditory canal of an ear and an external surroundings; the housing comprising: a pressure relay channel extending through the housing between the auditory canal and the external
• a pressure valve arranged in the pressure relay channel, the pressure valve arranged for switching between an open or closed position for allowing or preventing, respectively, an exchange of pressure between the auditory canal and the external surroundings; an acoustic generator arranged between the pressure valve and the auditory canal; the method comprising generating an acoustic signal into the auditory canal using the acoustic generator; measuring an internal pressure level in the auditory canal; and controlling a switching of the pressure valve wherein the pressure valve is switched to an open position when the measured internal pressure level is above a threshold pressure level.
• the method according to the second aspect may provide a user with the benefits of sealing the ear while hstening to audio playback, e.g. an improved cancellation of ambient noises, while at the same time providing the user with a measure of protection against excessive pressures in the auditory canal which may otherwise cause discomfort and/or damage to the user's ear.
• a method according to the second aspect may e.g. be provided by an audio listening device according to the first aspect.
• FIG 1 shows a schematic first embodiment of an audio listening device according to the first aspect.
• FIG 2 shows a schematic second embodiment of an audio listening device comprising a differential pressure sensor.
• FIG 3 shows a schematic third embodiment of an audio listening device comprising a pressure sensor with microphones.
• FIG 4 shows a schematic fourth embodiment that is a combination of the second and third embodiments.
• FIG 5 shows a schematic fifth embodiment similar to the fourth embodiment but comprising a second pressure valve.
• FIG 6 shows a schematic first embodiment of a housing for an audio listening device.
• FIG 7 shows a schematic second embodiment of a housing for an audio listening device.
• FIG 8 shows a schematic third embodiment of a housing for an audio listening device.
• FIG 9 shows a graph comparing sound pressure levels between an open and closed valve.
• the human ear is generally less sensitive for low frequency sounds between 20-200 Hz.
• An average listener may for example experience a possibly harmful sound of 100 dB at 50 Hz equally as loud as if it were only 80 dB at 1000 Hz.
• a sound pressure level (SPL) in an ear can be reduced in case it becomes too high by usage of a pressure valve in an otherwise pressure sealed earplug or earphones.
• the device may keep the orifice closed under safe usage conditions of a sealed headset and, in case the sound pressure in the ear becomes too high, the orifice may be opened. It was found that by opening an orifice of suitable size the sound pressure in the ear can be conveniently and effectively reduced to a safer level thus generating a safer headset that can be used with a variety of sound sources. It is noted that an acoustic valve was previously disclosed e.g. in international patent publications WO 2005/041831 and WO
• FIG 1 shows a first embodiment of an audio listening device 1.
• the audio listening device 1 comprises a housing 2, shaped to substantially form a pressure seal between an auditory canal 11 of an ear and an external surroundings 12. See also FIG 6 - 8.
• the housing 2 comprises a pressure relay channel 3 extending through the housing 2 between the auditory canal 11 and the external surroundings 12 arranged for relaying a pressure difference there between.
• a pressure valve 4 in the pressure relay channel 3 is arranged for switching between an open or closed position for allowing or preventing, respectively, an exchange of pressure between the auditory canal 11 and the external surroundings 12.
• An acoustic generator 9 between the pressure valve 4 and the auditory canal 11 is arranged for generating an acoustic signal into the auditory canal 11.
• the pressure valve 4 is controlled by a valve control comprising an actuator 5 arranged for switching the valve between the open and closed position and control logic 6 arranged for controlling the actuator 5.
• the control logic receives input from a pressure sensor 7, arranged for
• the control logic 6 is arranged for controlling the actuator 5 to switch the pressure valve 4 to an open position when the measured internal pressure level PI is above a threshold pressure level. In this way an excess pressure in the auditory canal may be prevented.
• the pressure sensor 7 is arranged in the pressure relay channel 3 for detecting a sound pressure level caused by the acoustic generator 9 so that the pressure valve 4 can be switched in dependence of the said sound pressure level.
• the acoustic generator 9 is arranged to direct its sound into the channel where the pressure detector 7 is located.
• control logic 6 may be arranged for controlling the actuator 5 to switch the pressure valve 4 to a closed position when the measured internal pressure level PI is below said threshold pressure level or below a lower pressure threshold. In this way an improved cancellation of ambient noises may be achieved when there is no excess pressure in the auditory canal.
• the internal pressure level PI may be influenced not only by ambient pressure
• sound pressure refers to a local pressure deviation from the average or
• the term "sound pressure level” refers e.g. to a logarithmic measure of the effective sound pressure of a sound relative to a reference value. It may be measured e.g. in decibels (dB) above a standard reference level, e.g. 20 ⁇ root mean square in air or 1 ⁇ under water. These and other reference levels may be defined e.g. in a standard such as ANSI Si.1-1994. It is thus to be appreciated that the measured internal pressure level may be a function of the internal sound pressure level in the auditory canal, e.g. the internal pressure level may increase proportionally with the internal sound pressure level.
• the pressure sensor 7 comprises a microphone arranged for measuring a sound pressure level (SPL). Sound waves registered by the microphone may be converted into electrical signals that are inputted into the control logic of the valve control. The control logic may convert these signals into corresponding pressure levels and control the pressure valve via the actuator according to the above specifications.
• SPL sound pressure level
• part of the pressure relay channel 3b may be cylindrical and sealed at an end by the pressure valve 4.
• the acoustic generator comprises an electro- acoustic transducer, e.g. an audio speaker, electrically connected to a frequency and/or amplitude modulated electric source that is comprised in a playback device, e.g. a music player.
• the valve control may be also arranged for opening the pressure valve in the pressure relay channel as a function of an electric signal received from the electric source. In this way a quicker response to fluctuations of a sound pressure level caused by sound waves generated by the acoustic generator may be achieved.
• the acoustic generator 9 comprises a balanced armature receiver.
• this may e.g. further increase electrical efficiency of the acoustic generator 9 and allow for a HiFi experience for the user at relatively low SPL.
• the actuator 5 may be e.g. electromechanically driven and/or comprise a piezo crystal. This may have an advantage that the actuator can be durable, energy efficient and quite small, e.g. small enough to fit into an ear bud.
• the threshold pressure level may be defined as an absolute pressure level or a pressure level difference.
• the threshold pressure level may be set at an absolute pressure value, e.g. 101.8 kPa (i.e. 0.5 kPa over the standard atmospheric pressure of 101.3 kPa), wherein the pressure valve opens when the measured pressure exceeds this (absolute) pressure value.
• the pressure threshold may be set relative to an external pressure level, e.g. the threshold pressure level may be set at 0.5 kPa above or below the external pressure level, wherein the pressure valve opens when the pressure difference exceeds this value.
• the threshold pressure level may be set in terms of a sound pressure level e.g.
• the threshold pressure level may be defined as a sound pressure level difference of 5 dB, e.g. wherein the pressure valve opens when the sound pressure level in the ear is at least 5 dB higher than that of the external surroundings.
• the pressure valve may open when the absolute pressure exceeds 101.8 kPa or exceeds the external pressure by more than 0.5 kPa.
• valve control is arranged to switch the pressure valve 4 to an open position when the measured internal pressure level including an internal sound pressure level caused by the acoustic generator 9 is above a relative threshold pressure level, wherein the said relative threshold pressure level is in the range of 0.1 - 10 kPa, preferably in the range of 0.3 - 5 kPa, more preferably in the range of 0.4 - 1 kPa, e.g. a threshold pressure level of 0.5 kPa is found to be a good compromise between preventing hearing damage whilst keeping a desired sound quality by not unnecessarily opening the pressure valve.
• valve control is arranged to switch the pressure valve 4 to an open position when the measured internal sound pressure level is higher than that of the external surroundings by a threshold amount in the range of 1-20 dB, preferably in the range of 2-10 dB, e.g. wherein the pressure valve opens when the sound pressure level in the ear is at least 5 dB higher than that of the external surroundings.
• FIG 2 shows a second embodiment of an audio listening device 1 according to the first aspect.
• the device 1 comprises a differential pressure sensor 7ab.
• the pressure sensor 7ab is arranged for measuring both the internal pressure PI in the auditory canal 11 and an external pressure level P2 of the external surroundings 12.
• the pressure valve 4 can be used to equalize the pressure in the ear by subtly opening the valve 4.
• the pressure could e.g. be measured by using MEMS pressure sensors which are able to measure small changes in pressure differences (e.g. 2 pa / 100 ms).
• suitable sensors are available commercially as the Alps HSPPAR or
• HSSPARC or the Bosch BMP 180 and Acuity AC3050 (differential). Some of these pressure sensors may be also suitable for measuring high amplitude 94 (dB) low-frequent ( ⁇ 200 Hz) sound pressure levels.
• a pressure level in the middle ear may be equilibrated with the external pressure level P2 via the Eustachian tubes.
• a pressure difference may occur between the outer ear and the middle ear.
• This pressure difference ⁇ may be felt by the user as an uncomfortable pressure on his eardrum that separates the outer and middle ear.
• a good measure may be obtained of the pressure felt by the user.
• these pressure differences may be either positive or negative, i.e. P1>P2 or P1 ⁇ P2. Either pressure difference may be
• the total pressure in the auditory canal 11 may be a sum or other combination of a static pressure level PI, e.g. influenced by the environment and a sound pressure level SI, e.g. influenced by sound waves, either external or produced by the acoustic generator 9.
• a static pressure level PI e.g. influenced by the environment
• a sound pressure level SI e.g. influenced by sound waves, either external or produced by the acoustic generator 9.
• a noise cancelling earplug device comprising a housing 2, shaped to substantially form a pressure seal between an auditory canal 11 of an ear and an external surroundings 12; the housing 2 comprising a pressure relay channel 3 extending through the housing 2 between the auditory canal 11 and the external surroundings 12 arranged for relaying a pressure difference there between; a pressure valve 4 arranged in the pressure relay channel 3, the pressure valve 4 arranged for switching between an open or closed position for allowing or preventing, respectively, an exchange of pressure between the auditory canal 11 and the external surroundings 12; and a valve control comprising an actuator 5 arranged for switching the valve between the open and closed position; and control logic 6 arranged for controlling the actuator 5; a pressure sensor 7, arranged for measuring an internal pressure level PI in the auditory canal 11; wherein the control logic 6 is arranged for controlling the actuator 5 to switch the pressure valve
• the pressure sensor 7 of the said ear plug device is arranged for measuring also an external pressure level P2 of the external surroundings 12; and the threshold pressure level is a function of the measured external pressure level P2 such that the control logic 6 is arranged for controlling the actuator 5 to open the pressure valve 4 when a pressure difference ⁇ between the internal and external pressure levels is higher than a threshold pressure difference.
• the pressure sensor of the earplug device may comprise a differential pressure sensor 7ab as shown.
• such an earplug device may provide the benefit of attenuating external noise while at the same time providing the user with a measure of protection against excessive pressures in the auditory canal which may otherwise cause discomfort and/or damage to the user's ear.
• An application of such an earplug device may be e.g. for passengers of an airplane.
• the passenger may use the earplug to attenuate noise from the airplane and/or the other passengers while not having to worry about excessive pressures on his ear drum as a result of ambient pressure fluctuations, e.g. during landing and take-off.
• Another application may be for musicians, e.g. playing trumpet, horn, woodwind etc. that may experience undesired pressure buildup in the ear when wearing
• FIG 3 shows a third embodiment of an audio listening device 1 wherein the pressure sensor comprises two microphones 7a and 7b.
• the microphone 7b of the pressure sensor is arranged for measuring an internal sound pressure level Si in the auditory canal 11.
• the microphone 7b of the pressure sensor is arranged for measuring an external sound pressure level S2 of the external surroundings 12.
• control logic is further arranged to close the pressure valve 4 or keep the pressure valve 4 closed when an external sound pressure level S2 exceeds an threshold sound pressure level value that may otherwise cause damage or discomfort to a user, e.g. a value of 85 dB or more.
• the pressure sensor may comprise a hydrophone for measuring an SPL under water.
• a hydrophone for measuring an SPL under water.
• Such an embodiment may e.g. be used for an underwater audio listening device.
• the pressure sensor and/or the control logic are arranged for time-averaging the measured pressures, e.g. over a time interval of 0.1 seconds or longer. It is to be appreciated that the time- averaged pressure, rather than e.g. the instantaneous pressure oscillations of impinging sound waves, may be indicative of the effective pressure felt by a user on his ear drum.
• This embodiment may be combined e.g. with a sensor comprising a microphone or hydrophone
• FIG 4 shows a fourth embodiment of an audio listening device 1.
• the audio listening device 1 comprises a differential pressure sensor 7ab arranged for measuring a pressure difference between a pressure level PI in an auditory canal 11, and a level pressure P2 of an external surroundings 12.
• the audio listening device further comprises a microphones 7a for measuring an internal sound pressure level S 1 in the auditory canal 11 and a microphone 7b for measuring an external sound pressure level S2 from the external surroundings 12.
• the audio listening device 1 comprises a pressure valve 4 and actuator 5 as discussed above.
• the control logic 6 comprised in the audio listening device 1 is arranged for receiving input from the differential pressure sensor 7ab and the microphones 7a and 7b.
• the control logic is further arranged to control the pressure valve 4 via the actuator 5 on the basis of this input.
• the pressure valve 4 is arranged for switching to intermediate cross-section openings between the open and closed positions thereby providing a variable cross-section opening in the pressure relay channel.
• the control logic 6 is arranged to control the pressure valve 4 such that, depending on parameters and measured input values valve is switched between a slightly open position for a controlled equalization of a pressure difference; or a substantially or fully open position to decrease a sound pressure in the auditory canal; or a substantially or fully closed position to enhance a sound quality and/or attenuate outside noise.
• control logic 6 controls the pressure valve 4 in accordance with parameters given in the following table:
• the pressure valve will not be substantially open when the external SPL is 5 dB or more above the internal SPL to protect a user from the excessive external SPL.
• the valve may in that case only be slightly opened while a pressure level difference ⁇ is more than 0.5 kPa to equilibrate the pressure Si in the auditory canal with the external pressure S2.
• a pressure level difference ⁇ is more than 0.5 kPa to equilibrate the pressure Si in the auditory canal with the external pressure S2.
• the pressure valve is kept substantially open while the SPL in the auditory canal is above 85 dB, to reduce said internal SPL in the auditory canal.
• the internal SPL is below 85 dB and the external SPL is less than 5 dB above the internal SPL, i.e.
• the pressure valve may be kept closed when the pressure difference between the auditory canal and the external surroundings is below 0.5 kPa and slightly open when the pressure difference is more than 0.5 kPa. In this latter mode the pressure valve is thus kept closed or slightly open to improve the audio quality experience of the user.
• control logic 6 is under the influence of control parameters, e.g. such as those given in the above table, to choose between
• substantially open may refer e.g. to a cross-section opening of the pressure valve 4 of more than 0.2 mm 2 , between 0.05 mm 2 and 0.2 mm 2 , and less than 0.05 mm 2 , respectively.
• the cross-section of the pressure valve 4 may be defined e.g. as the opening cross-section that is transverse to the airflow through the valve. Alternatively, the cross-section may be defined by the amount of air that runs through the pressure valve for a particular pressure difference over the pressure valve.
• the cross-section may be defined by the rate of equilibration (e.g. in Pa/s) of the pressure difference (e.g. in Pa) over the pressure valve.
• rate of equilibration e.g. in Pa/s
• pressure difference e.g. in Pa
• This latter definition may be useful e.g. if it is desired that the rate of equilibration does not exceed a certain maximum
• control logic 6 is arranged to control the pressure valve 4 such that the pressure difference ⁇ between the internal and external pressure levels is equilibrated with a controlled rate of less than 50 Pa/s, preferably 25 Pa/s . This rate may be smaller than a maximum equilibration rate for a fully open pressure valve.
• a sudden and uncontrolled pressure increase or decrease in the auditory canal may be prevented.
• Such a sudden pressure change may otherwise be uncomfortable and/or damaging to a user.
• Similar advantages of a controlled pressure difference equilibration rate may be experienced e.g. by divers that change depth.
• FIG 5 shows a fifth embodiment of an audio listening device 1 similar to the fourth embodiment of FIG 4, but further comprising a second pressure valve 14 arranged between the acoustic generator 9 and the auditory canal 11.
• the second pressure valve 14 may switched by the control logic via a second actuator 15 between an open and closed position for allowing or preventing, respectively, an exchange of pressure between the auditory canal 11 and the external surroundings 12.
• the control logic is arranged for controlling the second actuator 5 to switch the second pressure valve 14 to the closed position when a measured external sound pressure level S2 is above a specified threshold external sound pressure level threshold.
• the second pressure valve 14 may operate in addition to the first pressure valve 4, wherein the first pressure valve 4 is opened when an internal sound pressure level Si exceeds an internal sound pressure level threshold.
• the opening of the first pressure valve 4 may result in a decrease of the SPL in the auditory canal that may result from sound waves generated by the acoustic generator 9 while the closing of the second pressure valve 14 may result in a decrease of the SPL in the auditory canal that may be the result of external noise.
• control logic 6 may be arranged for
• control logic may also switch to a mode of
• the audio listening device may comprise a control override mechanism (not shown) arranged for overriding the control logic 6 and controlling the pressure valve 4 irrespective of input received from the pressure sensor.
• a control override mechanism (not shown) arranged for overriding the control logic 6 and controlling the pressure valve 4 irrespective of input received from the pressure sensor.
• a user may use an audio listening device such as disclosed in any of the above embodiment to seal the auditory canal 11 of his ear from the external surroundings 12, to generate an acoustic signal into the auditory canal 11, to measure an internal pressure level P I in the auditory canal 11, and to unseal the auditory canal 11 when the internal pressure level P 1 is above a threshold pressure level.
• an audio listening device 1 comprising a housing 2, shaped to substantially form a pressure seal between an auditory canal 11 of an ear and an external surroundings 12; the housing 2 comprising a pressure relay channel 3 extending through the housing 2 between the auditory canal 11 and the external surroundings 12; a pressure valve 4 arranged in the pressure relay channel 3; and an acoustic generator 9 arranged between the pressure valve 4 and the auditory canal 11; the method comprises
• the pressure valve 4 is switched to an open position when the measured internal pressure level P I, Si is above a threshold pressure level.
• the pressure valve 4 may be switched back to the closed position when the measured internal pressure level PI, Si gets below the threshold pressure level, e.g. for enhancing an audio listening experience.
• the internal pressure level P I may be measured in relation to an external pressure level P2 of the external surroundings and the auditory canal 11 is unsealed when a pressure difference between the internal and external pressure levels is higher than a threshold pressure difference.
• the said pressure difference may be equilibrated with a controlled rate smaller than 100 Pa/s, preferably smaller than 50 Pa/s.
• FIG 6 shows a first embodiment of a housing 2 for an audio listening device 1.
• the housing is shaped as an ear bud that can sealably fit at least partly into part of the auditory canal 11.
• the housing 2 may have shape that is customized to the shape of the exterior part of an auditory canal 11 such that the housing may effectively fit into the user's ear 13.
• the housing may thus form a pressure seal between the auditory canal 11 and an external surroundings 12.
• the pressure seal may opened by opening the pressure valve 4 that is arranged in the relay channel 3 extending through the housing 2 between the auditory canal 11 and the external surroundings 12.
• FIG 7 shows a second embodiment of a housing 2 for an audio listening device 1.
• the housing is again shaped as an ear bud that can sealably fit at least partly into part of the auditory canal 11.
• the housing 2 may be universal, i.e. adaptable to fit in differently sized and shaped (exterior parts of) auditory canals 11.
• the housing 2 may comprise e.g. a flexible material, able to adapt to the shape of an exterior part of the auditory canal 11 when inserted therein. Once inserted, the flexible material may expand to fill the said exterior part and form a pressure seal between the auditory canal 11 and the external surroundings 12.
• the currently shown embodiment of a universal housing 2 comprises circumferential flexible ribs of increasing diameter. These ribs may decrease in diameter when inserted in the ear a fit against the walls of an exterior part of the auditory canal.
• FIG 8 shows a third embodiment of a housing 2 for an audio listening device 1. In this embodiment the housing is not shaped as an ear bud such as in FIG 6 and FIG 7 but rather as (part of) a head phone. The housing 2 is shaped to form a barrier around the ear 13 separating the ear (and thus also the auditory canal 11) from the external surroundings 12. It is noted that the pressure relay channel 3 in this and the previous
• embodiments may also extend to the exterior side 12.
• part of the pressure relay channel 3 may be cylindrical and sealed at an end by the pressure valve 4.
• An advantage of such a configuration may be that the cylinder acts as a valve seat.
• the valve seat may be oriented such that when the valve is not powered an over pressure in the auditory canal e.g. generated by an acoustic generator keeps the valve closed.
• the valve seat may be oriented such that an over pressure in the external surroundings may keep the valve closed when not powered. This may be advantageous e.g. when a sudden pressure increase occurs in the external surroundings.
• FIG 9 shows a comparison of measurements of internal sound pressure levels S 1 measured in an auditory canal 11 (see previous figures) of an ear produced by an audio listening device according to the first aspect.
• the audio listening device was pressure sealed to the ear and comprised a pressure valve as described above.
• the solid curve 40 and the dashed curve 41 represent measurements using the device with a closed and opened pressure valve, respectively. Both curves measure the SPL in decibel (dB) at various frequencies F in Hertz (Hz). In the tested embodiment, the effect of the pressure valve was the highest at the lower frequencies. This is also where a typical user may not be aware of high sound levels, e.g. because the typical perception of lower frequencies may be less sensitive than for higher frequencies.
• a cross-section of a sound passage formed by the pressure relay channel is at least 0.5 mm 2 when the pressure valve is in an open position.

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• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Circuit For Audible Band Transducer (AREA)

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Cited By (14)

Citations (4)

• 2012
  • 2012-08-23 NL NL2009348A patent/NL2009348C2/en not_active IP Right Cessation
• 2013
  • 2013-08-22 WO PCT/NL2013/050609 patent/WO2014030998A1/fr not_active Ceased

Patent Citations (5)

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