U8008737650B2
`
`(12) United States Patent
`(10) Patent No.:
`US 8,737,650 B2
`
`Pedersen
`(45) Date of Patent:
`May 27, 2014
`
`(54) SYSTEM COMPRISING A PORTABLE
`ELECTRONIC DEVICE WITH A TIME
`FUNCTION
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`(75)
`
`Inventor: Michael Syskind Pedersen, Smorum
`(DK)
`
`(73) Assignee: Oticon A/S, Smorum (DK)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 210 days.
`
`(21) Appl.No.: 13/455,834
`
`(22)
`
`Filed:
`
`Apr. 25, 2012
`
`(65)
`
`Prior Publication Data
`
`US 2012/0275628 A1
`
`NOV. 1, 2012
`
`Related US. Application Data
`
`(60) Provisional application No. 61/478,959, filed on Apr.
`26, 2011.
`
`(30)
`
`Foreign Application Priority Data
`
`Apr. 26, 2011
`
`(EP) ..................................... 11163700
`
`(51)
`
`(2006.01)
`
`Int. Cl.
`H04R 25/00
`(52) US. Cl.
`USPC ........................................... 381/315; 381/312
`(58) Field of Classification Search
`USPC .................................. 381/3127315, 32(L321
`See application file for complete search history.
`
`LD
`
`5,065,321 A
`2002/0044669 A1
`2004/0116151 A1
`2006/0023904 A1
`2007/0009124 A1
`2009/0154743 A1
`2010/0067723 A1
`2011/0033071 A1
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`11/1991 Bezos et a1.
`4/2002 Meyer et a1.
`6/2004 Bosch et a1.
`2/2006 Fischer
`1/2007 Larsen
`6/2009 Lundh et a1.
`3/2010 Bergmann et a1.
`2/201 1 Larsen
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`FOREIGN PATENT DOCUMENTS
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`EP
`W0
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`10/2008
`1 981 253 A1
`11/2009
`WO 2009/135872 A1
`OTHER PUBLICATIONS
`
`issued for European Application No.
`European Search Report
`111637005 on Sep. 20, 2011.
`
`Primary Examiner 7 Suhan Ni
`(74) Attorney, Agent, or FirmiBuchanan lngersoll &
`Rooney PC
`
`ABSTRACT
`(57)
`A portable electronic device and an auxiliary device each
`having an interface allowing the establishment of a commu-
`nication link between them, at least to be able to transmit data
`representative of a status information from the auxiliary
`device to the portable electronic device, and-a method of of
`establishing a measure of an absolute elapsed time in a lis-
`tening device. The problem is solved in that the portable
`electronic device has a timing unit for determining a time
`interval and a memory for storing data, and wherein the
`auxiliary device has a master timing unit for providing a
`signal representative of the present time, and wherein the
`system is adapted to transfer a signal representative of the
`present time from the auxiliary device to the portable elec-
`tronic device and to store it in the memory.
`
`20 Claims, 3 Drawing Sheets
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`May 27, 2014
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`US 8,737,650 B2
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`US. Patent
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`US. Patent
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`US 8,737,650 B2
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`9 LDon —»-—x-- LDoff 9% LDon + LDOff —>e LDon 9 Sails
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`AuxD—T1
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`US 8,737,650 B2
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`1
`SYSTEM COMPRISING A PORTABLE
`ELECTRONIC DEVICE WITH A TIME
`FUNCTION
`
`TECHNICAL FIELD
`
`The present application relates to a portable electronic
`device comprising a local energy source, e.g. a listening
`device, in particular to the provision of an absolute time
`indication in such device. The disclosure relates specifically
`to a system comprising a portable electronic device and an
`auxiliary device, the portable electronic device and the aux-
`iliary device each comprising an interface allowing the estab-
`lishment ofa communication link between them, at least to be
`able to transmit data representative of a status information
`from the auxiliary device to the portable electronic device.
`The application furthermore relates to a method of establish-
`ing a measure of an absolute elapsed time in a portable elec-
`tronic device.
`
`The disclosure may e.g. be useful in applications where
`low power consumption is an important issue, e.g. in listening
`devices, such as hearing aids, headsets, ear phones, active ear
`protection systems, etc.
`
`BACKGROUND ART
`
`In portable electronic devices, e.g. listening devices, that
`are turned on and off according to need, in particular battery
`driven devices, e.g. to conserve power, an account of absolute
`time elapsed from a given start time (including the time where
`the device has been turned off) may be difficult to estimate
`with an appropriate precision in the device without a (power
`consuming) real time clock circuit.
`Some processing algorithms need an estimate ofa real time
`elapsed, which is longer than a typical time of operation
`(uptime) of the device in question.
`An uptime clock for measuring a time in which the device
`is in operation, and/or a power-up counter for counting a
`number of power-ups of device may be used to provide an
`estimate of a real time elapsed. An estimate of a real time
`elapsed may be based on the uptime multiplied by a prede-
`termined factor, depending on the application of the device in
`question. Alternatively an estimate of a real time elapsed may
`be based on the number of power-ups multiplied by a prede-
`termined time-value, depending on the application of the
`device in question, cf. e.g. US 2009/0154743 A1. These esti-
`mates are, however, subject to a substantial uncertainty due to
`the variance in use of the device from person to person and/or
`over time (e.g. from day to day).
`US 2002/0044669 A1 describes a hearing aid adapted for
`detecting whether it is located in the immediate vicinity of an
`external transmitter with and thereby automatically choosing
`a hearing aid program depending on the external transmitter.
`In addition, the current time of day and the day of the week
`may influence the choice of the active hearing aid program.
`US 2006/0023904 A1 describes a hearing aid adapted for
`emitting a voice signal to announce the current time of day,
`Preferably only the voice signal for the current time of day is
`saved in the hearing aid and to constantly update this voice
`signal by means of an external transmitter, preferably a
`remote controller. In this way, less memory space is thus
`required in the hearing aid for the time announcement.
`
`DISCLOSURE OF INVENTION
`
`It is proposed to provide an auxiliary device with a built-in
`clock. The auxiliary device is physically separate from the
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`portable electronic device and adapted to transfer time infor-
`mation to the portable electronic device. The auxiliary device
`may be a stand-alone device or e. g. be integrated with a
`battery charger, a cell phone, an audio gateway, an FM trans-
`mitter or a storage box or other device which the portable
`electronic device is expected to occasionally encounter. An
`internal clock ofthe portable electronic device can thereby be
`adjusted every time the portable electronic device is located
`near (the or) a matching auxiliary device. The term ‘when the
`portable electronic device is located near the (or an) auxiliary
`device’ is in the present context taken to mean whenever the
`two devices are able to communicate with each other (e.g.
`within an operational range of communication of a wireless
`link between them or when the two devices are electrically
`connected, e.g. via a galvanic connection).
`This has the advantage that the daily use and non-use
`pattern can be estimated. A further advantage is that an ab so-
`lute elapsed time (extending over a continuous time of opera-
`tion of the device) including down-time of the device, where
`the device is in a non-operational state (e. g. turned off) can be
`estimated. Algorithms or detectors needing information
`about elapsed time extending over more than a normal time of
`operation of the device, e.g. more than 8 hours or more than
`one day can thereby receive a more reliable input.
`The time synchronization with the portable electronic
`device can be established through a wired connection, e.g.
`where the auxiliary device form part of a charger or it can be
`established via wireless connection, e. g. where the auxiliary
`device form part of a storage box or an audio gateway or a
`cellular telephone or the like.
`An object of the present application is to make available a
`system and a method wherein an improved absolute time
`estimate is provided in a portable electronic device. It is an
`object of embodiments of the disclosure to provide an
`improved estimate of a time interval in a portable electronic
`device, said time interval being larger than an operating time
`of the portable electronic device from a power-on-time to a
`power-off-time.
`Objects of the application are achieved by the invention
`described in the accompanying claims and as described in the
`following.
`A system comprising a portable electronic device:
`An object of the application is achieved by a system com-
`prising a portable electronic device and an auxiliary device,
`the portable electronic device and the auxiliary device each
`comprising an interface allowing the establishment of a com-
`munication link between them, at least to be able to transmit
`data representative of a status information from the auxiliary
`device to the portable electronic device, wherein the portable
`electronic device comprises a timing unit for determining a
`time interval and a memory for storing data, and wherein the
`auxiliary device comprises a master timing unit for providing
`a signal representative of the present time, and wherein the
`system is adapted to transfer said signal representative of the
`present time from the auxiliary device to the portable elec-
`tronic device and to store it in said memory.
`This has the advantage that an elapsed time, including a
`time where the portable electronic device has been turned off,
`can be estimated by the device itself.
`Preferably, the portable electronic device is adapted for
`monitoring and storing an operating time from a power-on-
`time to a power-off—time of operation of the portable elec-
`tronic device.
`
`Preferably, the system is adapted to transfer a signal rep-
`resentative ofthe present time from the auxiliary device to the
`portable electronic device and to store it in saidmemory when
`the portable electronic device (or devices in case of a binaural
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`US 8,737,650 B2
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`3
`system) is connected to the auxiliary device (e.g. according to
`a predefined scheme) or at the request of a user, e. g. Via a user
`interface on the auxiliary device or on the listening device.
`Thereby the daily use and non-use pattern of the portable
`electronic device can be estimated.
`
`In an embodiment, the signal representative of the present
`time is transferred automatically. Alternatively it may be
`transferred at the request of the user via a user interface. In an
`embodiment, the portable electronic device and/or the auxil-
`iary device comprises a user interface adapted for allowing
`such initiation of the transfer of the signal representative of
`the present time.
`Preferably a measure of the absolute time elapsed from
`said reference start time is provided by the portable electronic
`device, e.g. by the timing unit.
`An estimate of the daily use and non-use pattern of the
`portable electronic device may e.g. include estimates of accu-
`mulateduse (where the portable electronic device is in normal
`use (powered on)) and non-use (where the portable electronic
`device is NOT in normal use (powered off)) pattern. It may
`further include a number of times within a given time interval
`the portable electronic device has been powered on (and off),
`average use and non-use times, etc.
`Preferably, the memory is a non-volatile memory.
`Preferably a reference start time is stored in the memory of
`the portable electronic device. In an embodiment, the refer-
`ence start time is stored in a memory ofthe portable electronic
`device during an initialization and/or a customization proce-
`dure (e.g. a fitting procedure of a listening device, e.g. a
`hearing aid). In an embodiment, a reference start time is
`stored in the memory of the portable electronic device by the
`auxiliary device during a specific initialization procedure
`(e. g. a first encounter ofthe portable electronic device with an
`auxiliary device, e.g. a pairing procedure authorizing the two
`devices to exchange data). In an embodiment, the reference
`start time is representative of, such as equal to, the present
`time at the time of storage of the start time in the device in
`question. In an embodiment, the reference start time corre-
`sponds to an initial time of operational use of the portable
`electronic device.
`
`In an embodiment, the system is adapted to provide that a
`linking procedure of the communication link between the
`auxiliary and portable electronic device comprises an identi-
`fication of a predefined security key in at least one of the
`devices, e.g. in the portable electronic device, e.g. in both
`devices. In an embodiment, the predefined security key is a
`predefined security key of the auxiliary device, e.g. in the
`form of a number of encrypted or non-encrypted bits. The
`complexity of the security key (including its length) can
`advantageously be adapted to the level of security of the
`application in question. An auxiliary device and a portable
`electronic device are said to be paired or matched, ifthey have
`been provided with corresponding security keys.
`In an embodiment,
`the portable electronic device is
`adapted to store in the memory a present time received from
`the auxiliary device as a last update of the current time
`(termed an ‘update time’). In an embodiment, the portable
`electronic device is adapted to erase a previous value of the
`last update of the current time when a newer value of the
`present time has been received. In an embodiment, the listen-
`ing device is adapted to store a number Nm of subsequently
`received present time values in the memory as the latest
`updates of the current time. In an embodiment, the listening
`device is adapted to erase the oldest of the Nm stored latest
`updates of the current time when a new present time value is
`received from the auxiliary device. In an embodiment, the
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`reference time is the oldest of the update times stored in the
`memory. In an embodiment, the reference time is the last
`stored update time.
`Preferably, the portable electronic device is adapted to
`monitor and store in the memory an estimate of the accumu-
`lated operating time ofthe portable electronic device (e. g. the
`time the portable electronic device has been turned on and
`being in a functional state, e.g. the time that the battery
`voltage has been sufficiently large for the portable electronic
`device to operate) relative to said reference start time and/or
`to one of said previously stored latest update time(s). An
`estimate ofthe accumulated operating time from a given start
`time is a summation of individual time intervals of operation
`(i.e. the ‘on—time’ of the portable electronic device) from that
`start time. In an embodiment, the portable electronic device is
`adapted to determine a relative operating time Top] (OSTOPV,
`r51), e. g. as the accumulated operating time over a real time
`interval divided by the real time interval. This figure can e.g.
`be used to compensate a time constant determined based on
`the operating time of the device for the non-operating time of
`the device where the device has been turned off (e. g. by
`multiplying the time constant in question with the relative
`operating time TOPJ). To account for small actual use times
`(relative operating times close to 0), a compensation algo-
`rithm such as MAX[T0P~T0PJ; Tmm] may be used, where TOP
`is a parameter (e.g. a time constant) estimated during normal
`operating use (assuming a continuous on-time) and Tm." is a
`minimum value of the parameter in question. In an embodi-
`ment, the real time interval is counted from the reference start
`time to the latest update time. In an embodiment, the real time
`interval is counted from an older update time to the latest
`update time. In an embodiment, the real time interval is larger
`than or equal to one day, e. g. larger than or equal to one week,
`e.g. larger than or equal to two weeks. In an embodiment, the
`real time interval is estimated as a'errev'l'U —0t)-rTCW_, where
`(X is a fading constant between 0 and l, e.g. equal to 0.5 and
`errev and rTCW are the previous and current real time esti-
`mates, respectively.
`the portable electronic device is
`In an embodiment,
`adapted to estimate an absolute time elapsed based on said
`start time and/or said previously stored update time(s). In an
`embodiment, the portable electronic device is adapted to esti-
`mate an absolute time elapsed from a given absolute point in
`time, e. g. from said start time or from one of said previously
`stored update time(s) to a later present time.
`In an embodiment,
`the portable electronic device is
`adapted to estimate an absolute time span wherein the por-
`table electronic device has been in a non-operational state
`from a given absolute point in time, e.g. from said start time
`or from one of said previously stored update time(s), and from
`an estimate of the accumulated time of operation of the por-
`table electronic device relative to said given absolute point in
`time. The time span may e. g. be estimated up to a stored
`update time, e. g. to the present time (e.g. the last update time).
`In an embodiment, an absolute point in time is defined by
`a time of day and a date. In an embodiment, the date is
`specified as a day-month-year. In an embodiment, the date is
`specified as a number of days from a predefined start date. In
`an embodiment, a time of the day is specified as an indication
`of the time elapsed (e.g. the number of hours or minutes or
`seconds) from a predefined time of the day, e.g. from mid-
`night. In an embodiment, the time elapsed is defined as a
`number of hours or as a number minutes or as a number of
`seconds or as combination thereof.
`
`In an embodiment, the auxiliary device forms part of a
`communication device, e.g. a cellular telephone or an audio
`transmitter (e.g. an FM transmitter). In an embodiment, the
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`US 8,737,650 B2
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`5
`auxiliary device forms part of an audio gateway device
`adapted for receiving a multitude of audio signals (e.g. from
`an entertainment device, e.g. a TV or a music player, from a
`telephone apparatus, e. g. a mobile telephone, or from a com-
`puter, e.g. a PC) and adapted for selecting and/or combining
`an appropriate one of the received audio signals (or combi-
`nation of signals) for transmission to the portable electronic
`device, e.g. a listening device. In an embodiment, the auxil-
`iary device forms part of a charging station (e.g. for charging
`a rechargeable battery of the portable electronic device(s))
`and/or a storage box for one or more (e. g. two) portable
`electronic devices or a remote control for the portable elec-
`tronic device.
`
`the auxiliary device is adapted to
`In an embodiment,
`receive a signal representative of the present time from
`another device, e.g. from a cell phone or from a radio time
`signal (e.g. DCF77 or MSF). In an embodiment, the auxiliary
`device comprises a real time clock circuit and a battery ensur-
`ing a constant functioning of the clock. Preferably the auxil-
`iary device is adapted to provide that the signal representative
`ofthe present time does not change with changing time zones
`and/or summer/winter time.
`
`In an embodiment, the auxiliary device comprises a display
`and is adapted to show the present time generated or received
`by the auxiliary device in the display.
`In an embodiment, the system is adapted to provide that the
`portable electronic device receives the signal representative
`of the present time from the auxiliary device via an interme-
`diate device, where the auxiliary device and the intermediate
`device, and the intermediate device and the portable elec-
`tronic device are adapted to be able to establish a communi-
`cation link between them (e.g. a fully or partially wireless
`link), at least enabling a transmission ofdata representative of
`a present time from the auxiliary device to the portable elec-
`tronic device. In an embodiment, the intermediate device
`comprises an audio gateway and/or a remote control. In an
`embodiment, the auxiliary device form part of a cell phone,
`transmitting the signal representative of the present time to
`the intermediate device. In an embodiment, the intermediate
`device comprises an audio gateway adapted to relay the signal
`representative ofthe present time from the auxiliary device to
`the portable electronic device. In an embodiment, the system
`comprises the intermediate device.
`In an embodiment, the portable electronic device and/or
`the intermediate device comprises a display and is/are
`adapted to show an estimate of the present time based on a
`signal representative of the present time received from the
`auxiliary device in the display of device in question. In an
`embodiment, the portable electronic device and/or the inter-
`mediate device is/are adapted to display an estimate of the
`accumulated operating time of the portable electronic device.
`In an embodiment, the portable electronic device and/or the
`intermediate device is/are adapted to display an estimate ofan
`absolute time elapsed. In an embodiment, the portable elec-
`tronic device and/or the intermediate device is/are adapted to
`display an estimate of the relative operating time of the por-
`table electronic device.
`
`In an embodiment, the portable electronic device is a
`device comprising a local energy source, e.g. a battery, e.g. a
`rechargeable battery. In an embodiment, the portable elec-
`tronic device is a low power device. The term ‘low power
`device’ is in the present context taken to mean a device whose
`energy budget is restricted, e.g. because it is a portable device
`comprising a local energy source of limited size (e.g. with a
`maximum capacity of 1000 mAh, such as 500 mAh),
`whichiwithout being exchanged or rechargediis oflimited
`duration (the limited duration being e.g. of the order of hours
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`1 or 3 or 7 or 10 days (during normal
`or days, e.g. max.
`operation of the device), such duration being limited com-
`pared to the expected life time of the device). In an embodi-
`ment, the energy source of the portable electronic device is
`removed of disconnected, when the portable electronic
`device is not in operational use (whereby data that are not
`stored in a non-volatile memory are lost). In an embodiment,
`the portable electronic device has a maximum outer dimen-
`sion of the order of 0.15 m (e.g. a handheld entertainment
`device). In an embodiment, the portable electronic device has
`a maximum outer dimension of the order of 0.08 m (e.g. a
`head set). In an embodiment, the portable electronic device
`has a maximum outer dimension of the order of 0.04 m (e.g.
`a hearing instrument).
`The portable electronic device and the auxiliary device
`each comprise an interface (including appropriate antenna
`and transceiver circuitry) to allow a communication link to be
`established between them, at least for transmitting informa-
`tion about the current time from the auxiliary device to the
`portable electronic device.
`In an embodiment, the portable electronic device com-
`prises an antenna and transceiver circuitry for wirelessly
`receiving a direct electric input signal. In an embodiment, the
`portable electronic device comprises a (possibly standard-
`ized) electric interface (e.g. in the form of a connector) for
`receiving a wired direct electric input signal. In an embodi-
`ment, the portable electronic device comprises demodulation
`circuitry for demodulating the received direct electric input to
`provide a direct electric input signal representing an audio
`signal and/or a control or status signal e.g. for setting an
`operational parameter (e.g. volume) and/or a processing
`parameter of the portable electronic device, possibly includ-
`ing said time information.
`In general, a wireless link established between the auxil-
`iary device and the portable electronic device can be of any
`type. In the present disclosure, the wireless link is used under
`power constraints in that at least one of the devices comprises
`a portable electronic (typically battery driven) device. In an
`embodiment, the wireless link is a link based on near-field
`communication, e.g. an inductive link based on an inductive
`coupling between antenna coils of the transmitter and
`receiver parts ofthe auxiliary and portable electronic devices,
`respectively. In another embodiment, the wireless link is
`based on far-field, electromagnetic radiation. In an embodi-
`ment, the communication via the wireless link is arranged
`according to a specific modulation scheme, e.g. an analogue
`modulation scheme, such as FM (frequency modulation) or
`AM (amplitude modulation) or PM (phase modulation), or a
`digital modulation scheme, such as ASK (amplitude shift
`keying), e.g. On-Off keying, FSK (frequency shift keying),
`PSK (phase shift keying) or QAM (quadrature amplitude
`modulation). In an embodiment, the communication between
`the devices is arranged to follow an analogue or a digital
`communication standard, e.g. wireless IEEE 802.11 or Zig-
`Bee or Bluetooth or DECT, or to follow a proprietary scheme.
`In an embodiment, the portable electronic device com-
`prises a portable entertainment device and/or a listening
`device, e.g. a hearing instrument, a headset, an active ear
`protection device or a combination thereof.
`In an embodiment,
`the portable electronic device is
`adapted to provide a frequency dependent gain to compensate
`for a hearing loss of a user. In an embodiment, the portable
`electronic device comprises a signal processing unit for
`enhancing the input signals and providing a processed output
`signal.
`In an embodiment, the system is adapted for providing a
`timing input to algorithms or detectors needing information
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`US 8,737,650 B2
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`7
`about elapsed time extending over more than a time of opera-
`tion of the portable electronic device, e.g. more than 8 hours
`or more than one day, such as more than 1 month, such as
`more than 6 months. In an embodiment, said timing input
`comprises an estimate of the absolute time elapsed from said
`reference start time to a present time.
`In an embodiment,
`the portable electronic device is
`adapted to provide an estimate of the absolute time elapsed
`from a later point in time than the reference start time to the
`present time (or to a time earlier than the present time).
`In an embodiment, the portable electronic device com-
`prises an input transducer for converting an input sound to an
`electric input signal. In an embodiment, the portable elec-
`tronic device comprises a directional microphone system, e.g.
`adapted to separate two or more acoustic sources in the local
`environment of the user wearing the portable electronic
`device. In an embodiment, the directional system is adapted
`to detect (such as adaptively detect) from which direction a
`particular part of the microphone signal originates. This can
`be achieved in various different ways as e. g. described in the
`prior art. In an embodiment, the directional microphone sys-
`tem comprises an algorithm for matching the two or more
`microphones as a function of time. In an embodiment, the
`algorithm for matching the two or more microphones is
`adapted to receive a measure (e. g. from the timing unit) of the
`absolute time elapsed from a given start time (e. g. the refer-
`ence start time).
`In an embodiment, the portable electronic device (e.g. a
`listening device), e.g. the signal processing unit, comprises an
`algorithm for estimating a parameter related to child growth,
`e.g. to the growth of an ear canal of the child over time. In an
`embodiment, the algorithm for estimating the growth of an
`ear canal of the child over time is used to estimate points in
`time, where a modification of parameters of the portable
`electronic device (e.g. a listening device, such as a hearing
`instrument), e.g. gain parameters, such as maximum power
`output (MPO), is appropriate (cf. e.g. US 2009/01 54743 Al).
`In an embodiment, such modification is based on a measure of
`the absolute time elapsed from a given start time (e.g. the
`reference start time) provided by the portable electronic
`device (e. g. the timing unit). In an embodiment, the algorithm
`for estimating the growth ofan ear canal ofthe child over time
`is used to estimate a parameter related to leakage of sound
`from an output transducer to an input transducer of the listen-
`ing device.
`In an embodiment, the listening device is adapted to issue
`an alarm signal related to a time.
`In an embodiment, the listening device is adapted to issue
`an alarm signal when a predefined time has elapsed since a
`given absolute point in time, e.g. since said start time or from
`one of said previously stored update time(s). This may e.g. be
`used to indicate to a user a (future) point in time that is related
`to an absolute time. In an embodiment, the listening device is
`adapted to issue an alarm signal when the accumulated oper-
`ating time is larger than a predefined accumulated operating
`time. This can e.g. be used to indicate an estimate of a time for
`changing of recharging the battery.
`In an embodiment,
`the listening device comprises an
`acoustic dose estimator and is adapted to issue an alarm signal
`when a predefined accumulated acoustic does has been
`exceeded.
`
`In an embodiment, the listening device comprises an out-
`put transducer for converting an electric signal to a stimulus
`perceived by the user as an acoustic signal. In an embodiment,
`the output transducer comprises a number of electrodes of a
`cochlear implant or a vibrator of a bone conducting hearing
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`8
`device. In an embodiment, the output transducer comprises a
`receiver (speaker) for providing the stimulus as an acoustic
`signal to the user.
`the listening device comprises an
`In an embodiment,
`acoustic (and/or mechanical) feedback suppression system.
`In an embodiment, the listening device further comprises
`other relevant functionality for the application in question,
`e.g. compression, noise reduction, etc.
`Use:
`
`In an aspect, use of a system as described above, in the
`detailed description of ‘mode(s) for carrying out the inven-
`tion’ and in the claims, is moreover provided.
`In an embodiment, the system is used in a hearing aid
`system comprising one or more hearing instruments, e.g. in a
`binaural hearing aid system. In an embodiment, the system is
`used in a hearing aid system comprising an audio gateway.
`A method:
`
`A method of establishing a measure of an absolute elapsed
`time in a portable electronic device, the portable electronic
`device forming part of a system comprising the portable
`electronic device and an auxiliary device, the portable elec-
`tronic device and the auxiliary device each comprising an
`interface allowing the establishment of a communication link
`between them, at least to be able to transmit data representa-
`tive of a status information from the auxiliary device to the
`portable electronic device is furthermore provided by the
`present application. The method comprises
`providing in the auxiliary device a signal representative of
`the present time;
`transmitting said signal representative of the present time
`to the portable electronic device;
`receiving said signal representative of the present time in
`the portable electronic device;
`extracting and storing data representative of the present
`time in the portable electronic device;
`determining in the portable electronic device an absolute
`time interval based on said data representative of the
`present time received from the auxiliary device.
`It is intended that the structural features of the system
`described above, in the detailed description of ‘mode(s) for
`carrying out the invention’ and in the claims can be combined
`with the method, when appropriately substituted by a corre-
`sponding process and vice versa. Embodiments ofthe method
`have the same advantages as the corresponding system.
`In an embodiment, the method comprises storing a time
`reference in the portable electronic device, the time corre-
`sponding to an initial time of use of the portable electronic
`device (termed a reference start time).
`The signal representative of the present time is preferably
`(automatically transmitted from the auxiliary device and)
`received in the portable electronic device when the portable
`electronic device is connected to the auxiliary device. Alter-
`natively to an automatic transfer, the transfer may be initiated
`by a user (e.g. via a user interface on the portable electronic
`device and/or on the auxiliary device).
`Preferably, the absolute time interval is determined in the
`portable electronic device based on the data representative of
`the present time receiv