Hearing device with active vent click compensation

Abstract

A hearing device has an ear plug for insertion into an ear canal of a user of the hearing device. The ear plug comprises a vent having a vent valve device configured to open or close the vent. The hearing device is configured to obtain a predetermined audio signal representing a sound emitted by the vent when the vent valve device is being manipulated. The signal processor is configured to output a phase-inverted version of the predetermined audio signal to the receiver substantially at the same time as the vent valve device is manipulated, thus cancelling out the sound of the vent. The predetermined audio signal may be obtained during manufacture of the hearing device or it may be picked up by an in-the-ear microphone. Accordingly, the unpleasant sound of a vent being opened or closed while the hearing device is worn by a user is reduced or eliminated.

Claims

1. A hearing device having an ear plug for insertion into an ear canal of a user of the hearing device, the hearing device comprising: a first microphone; a signal processor; a memory; a controller; and a receiver; wherein the ear plug comprises a vent having a vent valve device configured to open or close the vent, the controller being configured to manipulate the vent valve device to a first position or a second position based on a first signal from the signal processor; wherein the hearing device is configured to obtain a predetermined audio signal representing a sound emitted by the vent when the vent valve device is manipulated between the first position and the second position, and wherein the predetermined audio signal is stored in the memory; and wherein the signal processor is configured to access the predetermined audio signal in the memory, and to output a phase-inverted version of the predetermined audio signal to the receiver substantially at a same time as the vent valve device is manipulated.

2. The hearing device according to claim 1, wherein the phase-inverted version of the predetermined audio signal output by the signal processor when the vent valve device is manipulated to the first position is different from the phase-inverted version of the predetermined audio signal output by the signal processor when the vent valve device is manipulated to the second position.

3. The hearing device according to claim 1, wherein the receiver is in the ear plug.

4. The hearing device according to claim 1, wherein the first position of the vent valve device is an open position, and the second position of the vent valve device is a closed position.

5. The hearing device according to claim 1, wherein the first position of the vent valve device is a closed position and the second position of the vent valve device is an open position.

6. The hearing device according claim 1, wherein the phase-inverted version of the predetermined audio signal is configured to at least partially or completely cancel out sound emitted by the vent valve device whenever the vent valve device is manipulated.

7. The hearing device according to claim 1, wherein the predetermined audio signal is obtained during manufacture of the hearing device, and wherein the predetermined audio signal stored in the memory is accessible to the signal processor of the hearing device.

8. The hearing device according to claim 1, wherein the ear plug comprises a second microphone, wherein the second microphone is configured to pick up the sound emitted by the vent when the vent valve device is manipulated, and wherein the hearing device is configured to store a representation of the sound picked up by the second microphone as the predetermined audio signal in the memory.

9. The hearing device according to claim 1, further comprising a wireless transceiver.

10. The hearing device according to claim 9, wherein the wireless transceiver is configured to receive at least one instruction from an external device, the at least one instruction causing the signal processor to send the first signal to the controller for manipulating the vent valve device, and to output the phase-inverted version of the predetermined audio signal to the receiver substantially at the same time as the vent valve device is manipulated.

11. A method of operating a hearing device comprising a first microphone, a signal processor, a memory, a receiver, and a controller for manipulating a vent valve device in a vent of an ear plug of the hearing device, the method comprising: obtaining a predetermined audio signal representing a sound of the vent when the vent valve device changes position, wherein the predetermined audio signal is stored in the memory; providing a first signal from the signal processor to the controller to manipulate the vent valve device; and outputting a phase-inverted version of the predetermined audio signal to the receiver substantially at a same time as the vent valve device is manipulated.

12. The method according to claim 11, wherein the predetermined audio signal corresponding the vent valve device changing from an open position to a closed position is different from the predetermined audio signal corresponding with the vent valve device changing from the closed position to the open position.

13. The method according to claim 11, wherein the predetermined audio signal is obtained during manufacture of the hearing device, and wherein the predetermined audio signal is obtained by: determining the sound of the vent valve device changing position; and converting the determined sound into the predetermined audio signal.

14. The method according to claim 11, wherein the act of obtaining the predetermined audio signal is performed during fitting of the hearing device, and wherein the act of obtaining the predetermined audio signal comprises: manipulating the vent valve device to change position; picking up the sound of the vent valve device changing position using a second microphone; and converting the sound from the second microphone into the predetermined audio signal.

15. The method according to claim 11, wherein the hearing device comprises a wireless transceiver, and wherein the method further comprises receiving an instruction to manipulate the vent valve device via the wireless transceiver.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The hearing device is now described in greater details with respect to the drawings, wherein:

(2) FIG. 1 shows a prior art hearing device having an active vent;

(3) FIG. 2 shows a principle block schematic of a hearing device with vent click compensation;

(4) FIG. 3 shows a flowchart illustrating providing an anti-phase sound in a hearing device;

(5) FIG. 4a and FIG. 4b are timing diagrams showing concurrency of a vent sound and an anti-phase sound,

(6) FIG. 5a illustrates a longitudinal cut through an ear plug having an active vent in an open position, and

(7) FIG. 5b illustrates a longitudinal cut through an ear plug having an active vent in a closed position.

DETAILED DESCRIPTION

(8) Various embodiments are described hereinafter with reference to the figures. Like reference numerals refer to like elements throughout. Like elements will, thus, not be described in detail with respect to the description of each figure. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

(9) FIG. 1 shows a prior art ear plug 1 intended for a hearing device, having a receiver 2 for reproducing sounds for a user. The receiver 2 has an exchangeable wax guard 3 mounted in an opening (not shown) in front of the receiver 2. The purpose of the wax guard 3 is to prevent cerumen and moisture from the ear canal of the user to enter the ear plug 1, potentially damaging the receiver 2. Adjacent to the receiver 2 is a vent 4 having a vent valve device 6. The vent valve device 6 may change the acoustic impedance of the vent 4 by assuming one of two positions: One position corresponding to an open vent, and another position corresponding to a closed vent. The position of the vent valve device 6 is preferably manipulated electrically. The receiver 2 is connected to a hearing device (not shown in FIG. 1) via a receiver wire 5 for receiving an electrical signal representing sound to be reproduced acoustically by the receiver 2.

(10) During use, the vent valve device 6 may, in a first example, be in the position corresponding to an open vent. This provides the user with both the benefits end the disadvantages of a hearing device having a vent. In some cases, e.g. when listening to music, a vent may be a disadvantage to the user, e.g. due to the poor low-frequency reproduction of sounds associated with a vent, as stated earlier. In this case, the user may beneficially instruct the hearing device to move the vent valve device 6 to the position corresponding to a closed vent, advantageously performing the instruction by selecting a hearing device program among a plurality of available hearing device programs, said selected hearing device program comprising an internal instruction to close off the vent 4 by moving the vent valve device 6 to the position corresponding to a closed vent. In another case, the user may wish for the vent 4 to be open and thus select another hearing device program comprising an internal instruction to move the vent valve device 6 to the position corresponding to an open vent. Such a program may, beneficially, be tailored to have the hearing device perform optimally in e.g. conversational situations where e.g. the occlusion effect associated with a closed or absent vent may present problems for the user.

(11) Despite the obvious benefits of having an active vent in a hearing device there exists at least one drawback: The vent valve device 6 generates an air pressure wave, i.e. a sound, whenever the vent valve device 6 is opened or closed due to the occurrence of an inherent momentary change in air pressure within the ear canal of the user wearing the hearing device with the ear plug 1 placed in his or her ear canal due to the manipulation of the vent valve device 6. This sound may present itself as a popping or clicking sound which may be very discomforting to the user wearing the hearing device while the vent valve device 6 is being opened or closed.

(12) FIG. 2 illustrates schematically an ear plug 1 shown as an embodiment of an ITE hearing device. The hearing device is adapted for alleviating a clicking sound emitted by a vent valve device when it is opened or closed. During use, the ITE hearing device is placed in an ear canal of a user and is held in place partly by the shape of part of a user's outer ear 20 and partly by the shape of the ear canal itself. The ear plug 1 comprises an external microphone 8 for picking up acoustic signals from the surroundings and converting the acoustic signals into electrical signals. The external microphone 8 is connected to an A/D converter 21 for converting the electrical signals from the external microphone 8 into digital signals. The digital signals from the A/D converter 21 are output to a first input of a signal processor 22. The signal processor 22 is adapted to provide amplification of the signals picked up by the external microphone 8 according to a hearing loss prescription for the purpose of alleviating a hearing loss of the user by performing various computational operations on the digital signals from the A/D converter 21. The amplified signals are converted into a form suitable for being presented to a receiver 2, which is configured to convert the amplified signals into acoustic signals for the user to hear. A wireless transceiver 23 is configured to receive wireless signals picked up by an antenna 24 and convert the wireless signals into electrical signals which are fed to a second input of the signal processor 22. The wireless signals may e.g. be remote control signals or audio streaming signals intended for reproduction by the ITE hearing device.

(13) For reasons discussed in the foregoing, a vent 4 is embedded in the ear plug 1. The vent 4 is formed as a through-going canal in the body of the ear plug 1 and provides the ITE hearing device with an acoustic path from the outside of the ear plug 1 to the part residing within the ear canal of the user during use. The vent 4 has a vent valve device 6 capable of closing or sealing off the acoustic path provided by the vent 4. The vent valve device 6 is activated by a vent valve device controller 10 controlled by a dedicated, electrical output signal from the signal processor 22. Preferably, the vent valve device controller 10 is a binary device capable of manipulating the vent valve device 6 into one of two possible positions; Open or closed. This has the inherent advantage that the vent valve device controller 10 only draws current from the hearing device battery (not shown in FIG. 2) when opening or closing the vent valve device 6, thus saving power when manipulating the vent valve device 6. In some embodiments, information on the current position of the vent valve device 6 is detected by the vent valve device controller 10 and the information of the current position of the vent valve device 6 is then conveyed to the signal processor 22.

(14) The signal processor 22 controls the vent valve device 6 by applying a suitable, electrical signal to the vent valve device controller 10, thereby closing the vent valve device 6 if it is in the open position or opening the vent valve device 6 if it is in the closed position. When the vent valve device 6 is manipulated in this manner, a sound is emitted from the vent 4 due to the momentary change in the air pressure in the ear canal as indicated in FIG. 2. In order to counteract the sound thus emitted by manipulating the vent valve device 6, the signal processor 22 is configured to simultaneously send out a predetermined audio signal substantially identical to the sound emitted from the vent 4, but of opposite phase. The two sounds then cancel each other out. Thus, ideally, when the air pressure contribution from the vent 4 increases, the air pressure contribution from the receiver 2 decreases correspondingly, and vice versa.

(15) The net result of sending out a phase-inverted, predetermined sound from the receiver 2 at the same time as opening or closing the vent valve device 6 is that the combined contributions in air pressure change from the vent 4 and the receiver 2, respectively, sums to zero in the ear canal of the user, thus reducing or eliminating the sound emitted from the vent 4 during opening or closing the vent valve device 6.

(16) The predetermined sound is stored in the hearing device memory (not shown in FIG. 2) accessible to the signal processor 22 and may, in some embodiments, be embedded into the software code to be executed by the signal processor 22 during manufacture of the hearing device. The opening or closing of the vent valve device 6 is usually carried out by the hearing device operating system as a result of receiving a wireless command via the wireless transceiver 23, e.g. from a wireless remote control (not shown in FIG. 2) of the hearing device. The command may either be a direct command instructing the vent valve device controller 10 to manipulate the vent valve device 6, or it may be a command to select another program in the hearing device different from the program currently being executed, said different program requiring the vent valve device 6 to assume the other position, i.e. being opened if it is closed, or vice versa, dependent on its current position. In both cases, the signal processor 22 is configured to obtain the predetermined sound from the hearing device memory and output a phase-inverted version of the predetermined sound to the receiver 2 to coincide with the signal processor 22 sending an activation signal to the vent valve device controller 10. Preferably, the predetermined sound is a first predetermined sound of the vent 4 when the vent valve device 6 is opened and a second predetermined sound of the vent 4 when the vent valve device 6 is closed.

(17) In an alternative embodiment, no predetermined sound is stored in the hearing device memory of the signal processor 22 during manufacture. Instead, a health care professional instructs the vent valve device controller 10 to open and close the vent valve device 6, respectively, in situ during fitting of the hearing device, respectively, so that the vent 4 emits a sound in either case. This instruction may e.g. be given by activating a special mode in the hearing device, said special mode preferably being made available as an option in the fitting software used by the healthcare professional to fit the hearing device to suit the user's hearing loss and other needs. The sound emitted by the vent 4 when the vent valve device 6 is opening or closing is then picked up by an internal microphone 9 of the hearing device and subsequently stored as a representation of a set of predetermined sounds in the hearing device memory for later, phase-inverted reproduction as an acoustic signal by the receiver 2 whenever the vent valve device 6 is manipulated, as suggested by the curves denoted ‘Sound from receiver’ and ‘Sound from manipulating vent’, respectively, in FIG. 2. This has the added benefit of enabling adaptation of the predetermined sound to various configurations of the size and shape of the ear plug 1, the vent 4, and the corresponding dimensions of the ear canal of the user. In this way it is ensured that the phase-inverted version of the predetermined sound generated by the receiver 2 is individually optimized with respect to the sound emitted by the vent 4.

(18) The procedure for compensating the sound of an active vent 4 in an ear plug 1 is now described in more detail with reference to FIGS. 2 and 3. FIG. 3 is a flowchart illustrating a method (such as an algorithm) for the application of a phase-inverted sound to reduce or eliminate a sound emitted by an active vent 4 in the signal processor 22 of a hearing device of the type shown in FIG. 2. In step 301 of the algorithm, the hearing device is initiated, a prescription for alleviating a hearing loss is loaded into the signal processor 22, and a default program is selected. In step 302, data representing the sound emitted by the vent 4 whenever the vent valve device 6 is manipulated is stored in the hearing device memory. It should be noted here that, in some embodiments, step 302 may be carried out during manufacturing of the hearing device, i.e. the data may already be present in the hearing device memory at the time the hearing device is put into service.

(19) In step 303, the current position of the vent valve device 6 is determined. If the vent valve device 6 is in the closed position, the method or algorithm branches out to step 304, where an instruction to open the vent 4 is expected by the signal processor 22. When an instruction to open the vent 4 is received, the method or algorithm proceeds to step 305, where the signal processor 22 sends a signal to the vent valve device controller 10 and, coincidentally, sends out the phase-inverted, predetermined sound corresponding to the sound of the vent valve device 6 opening. The method or algorithm then returns to step 303 to update the open position of the vent valve device 6 as the current state.

(20) If the vent valve device 6 is determined to be in the open position in step 303, the method or algorithm instead branches out to step 306, where an instruction to close the vent 4 is expected by the signal processor 22. When an instruction to close the vent 4 is received, the method or algorithm proceeds to step 307, where the signal processor 22 sends a signal to the vent valve device controller 10 and, coincidentally, sends out the phase-inverted, predetermined sound corresponding to the sound of the vent valve device 6 closing. The method or algorithm then returns to step 303 to update the closed position of the vent valve device 6 as the current state.

(21) FIG. 4a is a timing diagram showing an example of a sound emitted by a vent 4 when a vent valve device 6 therein is closing the vent, with reference to the embodiment shown in FIG. 2. The timing diagram has time marked along the x-axis and the air pressure marked along the y-axis. The scaling of the x-axis is chosen arbitrarily but may be e.g. 1 ms/mark or 100 ms/mark, preferably 10 ms/mark, in FIGS. 4a and 4b. When a signal to close the vent 4 is sent out at t=0, the vent valve device 6 exhibits a delay, mainly due to mechanical limitations, before it starts to move and the air pressure contribution from the vent 4 rises as a result until reaching a local maximum at time t=T1, where it begins to fall again. At time t=T2, the air pressure contribution from the vent 4 has dropped significantly below the nominal air pressure, reaching a local minimum. The air pressure contribution from the vent 4 then fluctuates up and down a few times in a damped vibration before settling at the nominal air pressure at t=T3.

(22) FIG. 4b is a timing diagram showing an example of the phase-inverted, predetermined sound emitted by a receiver 2 to counteract a sound emitted by the vent 4 when the vent valve device 6 is closing, with reference to the embodiment shown in FIG. 2. The timing diagram is aligned with the timing diagram in FIG. 4a for clarity, and the units are the same as the units in FIG. 4a. At t=0, the delay of the vent valve device 6 is mimicked by delaying the phase-inverted, predetermined sound from the receiver 2 a corresponding period before making the diaphragm of the receiver 2 move in the opposite direction of the vent valve device 6, and the air pressure contribution from the receiver 2 reproducing the phase-inverted, predetermined sound thus falls until it reaches a local minimum at time t=T1, where it begins to rise again. At time t=T2, the air pressure contribution from the receiver 2 has risen significantly above the nominal air pressure, reaching a local maximum. The air pressure contribution from the receiver 2 then continues to follow the opposite movements of the vent valve device 6 before settling at the nominal air pressure at t=T3.

(23) Together, the contribution in air pressure change from the vent 4 and the receiver 2 cancel each other out due to the fact that the outlet of the vent 4 and the outlet of the receiver 2 are both confined to the closed volume of the ear canal of the user. Thus, the unpleasant sound which may be experienced by the user when the vent valve device 6 is manipulated is hereby eliminated or at least greatly reduced while preserving the benefits of an active vent, as discussed previously.

(24) FIGS. 5a and 5b illustrates a longitudinal cut through a receiver housing 50 having an active vent, according to an embodiment. The receiver housing 50 has a substantially cylindrical shape and comprises a receiver 2 connected to hearing device circuitry (not shown) via a receiver wire 5 at the distal end of the receiver housing 50 and connected to one end of a receiver sound outlet tube 53 at the proximal end of the receiver housing 50. The other end of the receiver sound outlet tube 53 is held in place by a vent outlet 55. The active vent comprises a solenoid coil 51 and a permanent magnet 52 mounted on a vent valve device 6. The magnet 52 may be a toroidal magnet. A plurality of vent inlets 54 are dispersed in the receiver housing wall between the solenoid coil 51 and the vent outlet 55. The vent outlet 55 is embodied as a ring or inner bushel restricting the inner diameter of the proximal end of the receiver housing 50. A flange 56 is arranged at the proximal end of the receiver housing 50. The purpose of the flange 56 is to form a seal between an ear plug (not shown) and the receiver housing 50 when the receiver housing is mounted in the ear plug, e.g. in the manner illustrated in FIG. 1.

(25) The vent valve device 6 is configured to move between a first, open position, shown in FIG. 5a, and a second, closed position, shown in FIG. 5b. The vent valve device 6 and the permanent magnet 52 are mounted together on the receiver sound outlet tube 53 in a way that facilitates a sliding motion of the vent valve device 6 between the first, open position and the second, closed position. The sliding motion is initiated by applying an electric current to the solenoid coil 51 for creating a magnetic field attracting or repelling the permanent magnet 52. An electric current through the solenoid coil 51 in one direction attracts the permanent magnet 52, thereby opening the vent, and an electric current in the opposite direction through the solenoid coil 51 repels the permanent magnet 52, thereby closing the vent.

(26) In the first, open position of the vent valve device 6 shown in FIG. 5a, the solenoid coil 51 attracts the permanent magnet 52 towards the distal end of the receiver housing 50, thereby creating a passageway for air to flow between the plurality of vent inlets 54 and the vent outlet 55. Thanks to the sealing between the ear plug (not shown) and the receiver housing 50, said passageway is the only way air can escape an ear canal (not shown) when the ear plug and the receiver housing 50 is mounted in its intended place in the ear canal.

(27) In the second, closed position of the vent valve device 6 shown in FIG. 5b, the solenoid coil 51 repels the permanent magnet 52 towards the proximal end of the receiver housing 50, thereby closing said passageway between the plurality of vent inlets 54 and the vent outlet 55. When the edge of the vent valve device 6 abuts the rim of the vent outlet 55, the vent valve device 6 and the vent outlet 55 forms a seal trapping the air in the ear canal from the exterior.

(28) When the vent valve device 6 reaches the second, closed position as illustrated in FIG. 5b, it gives off a first clicking sound when it hits an end stop. According to several embodiments, this first clicking sound may be compensated by having the signal processor of the hearing device (not shown) simultaneously provide a predetermined, first sound signal to the receiver 2 cancelling out the clicking sound of the vent valve device 6.

(29) When the vent valve device 6 reaches the first, open position as illustrated in FIG. 5a, it gives off a second clicking sound when it hits the rim of the vent outlet 55. According to several embodiments, this second clicking sound may be compensated by having the signal processor of the hearing device simultaneously provide a predetermined, second sound signal to the receiver 2 cancelling out the second clicking sound of the vent valve device 6.

(30) In this way, a hearing device capable of compensating clicking sounds emitted by an active vent whenever the active vent is manipulated, is devised.

LIST OF PARTS

(31) 1. Ear plug 2. Receiver 3. Wax guard 4. Vent 5. Receiver wire 6. Vent valve device 8. External microphone 9. Internal microphone 10. Vent valve device controller 20. Part of outer ear 21. A/D converter 22. Signal processor 23. Wireless transceiver 24. Antenna 50. Receiver housing 51. Solenoid coil 52. Toroidal magnet 53. Receiver sound outlet tube 54. Vent inlet 55. Vent outlet 56. Flange 301. Start 302. Store sound 303. Check vent position 304. Closed; receive instruction to open vent 305. Closed; open vent and play sound of opening vent 306. Open; receive instruction to close vent 307. Open; close vent and play sound of closing vent