Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
  • H04R25/45—Prevention of acoustic reaction, i.e. acoustic oscillatory feedback
  • H04R25/453—Prevention of acoustic reaction, i.e. acoustic oscillatory feedback electronically
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
  • H04R25/50—Customised settings for obtaining desired overall acoustical characteristics
  • H04R25/505—Customised settings for obtaining desired overall acoustical characteristics using digital signal processing

Definitions

• the invention concerns a hearing aid of the kind disclosed in the preamble to claim 1 , which in reality means almost all types of hearing aids to be found on the market.
• BTE behind the ear aid
• ITE in the ear aid
• CIC completely in the canal aid
• hearing aids can be configured both as so-called analogue aids and as digital aids, and as aids with a combination of analogue and digital techniques.
• the present invention can be used in connection with almost any form of hearing aid.
• BTE and ITE hearing aids usually have a mechanical on/off arrangement, e.g. a pushbutton, so that the user can wait to switch the aid on until it is correctly placed and thus avoid the oscillation.
• CIC hearing aids are so small that they rarely have a specific on/off arrangement. Such aids are switched on when a battery is inserted in the battery compartment and the battery cover is subsequently closed. When the battery cover is closed, the hearing aid is immediately switched on, i.e. that these types of aids are switched on before they are placed in the ear canal. The user can thus not avoid the howling tone until the aid is in place, which can be very troublesome. The howling tone can be extremely disturbing especially for users of CIC hearing aids, since these are often used by people with a slight or a moderate hearing loss.
• Start up period is a time period that consists of the of sum two parts, namely
• the "inherent delay period" depends on the electronic design of the hearing aid, and the inherent delay is usually minimised during the design phase. If the hearing aid involved is of the analogue type, a charging of supply and coupling capacitors and possibly other components must take place before the aid is completely functional. If the aid involved is of the digital type, programmes or parts hereof must be read from non-volatile storage areas and transferred to volatile memory areas such as program RAM and/or data
• the "comfort delay period” is an additional time delay period wherein the acoustic signal from the microphone is, partly or wholly, prevented from reaching the sound transducer.
• the hearing aid comprises means which generate a special acoustic signal during or at least in part of a comfort delay period it is avoided that a user thinks that the aid is defective, that the battery is empty, or that the aid is incorrectly set if he is informed about the delay function. So instead of begin to adjust the aid during the delay period and perhaps hereby set it incorrectly, the user will wait for the aid to function.
• the user can ascertain, i.e. hear, that the aid is switched on and that it functions as it should, and in a number of seconds will be completely ready and functional. It is noted, that in a prior art device, such as disclosed in DE 19526175, the device is silent in the delay period, leaving a user in doubt, whether the device is able to function or not.
• the characteristics of the special acoustic signal are programmable, it is possible to input a preselected acoustic signal, via for example a PC, which is adapted to a certain user demands, e.g. the signal can be formed so the user can ascertain how great a part of the comfort delay period there remains.
• This special acoustic signal can f. ex. be a series of short tones ("beeps”) at periodic intervals.
• the characteristics of the special acoustic signal are programmable in the dependence of the users audiogram it s possible to adapt the acoustic signal in a way such that the acoustic signal can comprise tones that naturally must be at a frequency and with a sound pressure that can be heard by the user.
• the special acoustic signal f. ex. by adjusting the level of the individual frequency components in the signal as function of time.
• the electronic circuit comprises amplification means adapted for reducing an amplification of the hearing aid during the comfort delay period, it is possible to avoid the possible, troublesome oscillation in a simple manner, and further by configuring the hearing aid as disclosed in claim 5 claim, a suitable down-regulation of the amplification is achieved, depending on the type of hearing aid involved, the setting of the hearing aid and the user's hearing impairment etc., so that a completely individual setting is achieved for the individual hearing aid user.
• the delay is greater than 1 second, preferably greater than 3 seconds, or the comfort delay period is 5 - 30 seconds in length preferably 5 - 20 seconds, in order to adapt the aid to various users having different wishes.
• the hearing aid can be adjusted to be completely or partly silent in a sufficient time until it has been positioned correctly. The user can thus avoid hearing the howling tone directly in the ear, even though the hearing aid has been switched on before it is positioned correctly at or in the ear.
• the period must be so long that the user, after having inserted the battery and hereby having switched on the aid, is able to place it correctly in the ear canal before the aid functions as it is has been set with regard to amplification, frequency response etc.
• the length of the comfort delay period can also depend on the age of the user, or on how long the user has had the hearing aid etc.
• the length of the comfort delay period is set or chosen e.g. during the user's preliminary examination at the audiologist or the like, where the user can e.g. try different length.
• the hearing aid can also be arranged as stated in claim 10, that the delay period means are adapted to reduce the length of the start-up period based on an accumulated utilisation time of the hearing aid In this way the length of the start-up period will be reduced automatically, e.g. by some percent, each time the aid has been switched on a certain number of times since the last reduction.
• This possible, automatic reduction may, as stated in claim 11 , cease at a determined limit, e.g. when the comfort delay period has been halved in relation to the starting point.
• a determined limit e.g. when the comfort delay period has been halved in relation to the starting point.
• the setting of the start-up period and the characteristics of the special acoustic signal can naturally also be selected as stated in claim 12, and carried out when the user consults the dealer, the audiologist or other qualified people who have fitting equipment for the hearing aid.
• the setting can be individual and such that the signal tones transmitted are at a level and frequency which are optimal for the user, e.g. the fitting equipment can be arranged in such a manner that it automatically selects a signal type and level on the basis of the user's own audiogram.
• fig. 1 shows a simplified block diagram of a digital hearing aid with comfort delay period according to the invention
• fig. 2 is a flow diagram showing the start-up phase for the hearing aid in fig. 1.
• FIG. 1 An example of such a hearing aid according to the invention is shown schematically in block diagram form in fig. 1.
• the hearing aid which is designated in general by the reference figure 1 , contains one or more sound receivers 2, in the shown example two microphones 2a and a telecoil 2b.
• the analogue signals for the microphones are coupled to an analogue- digital converter circuit 3, which contains an analogue-digital converter 4 for each of the microphones.
• the digital signal outputs from the analogue-digital converters 4 are coupled to a common data line 5, which leads the signals to a digital signal processing and adapter circuit 6.
• This circuit which for example can be in the form of a digital signal processor (DSP), and which is explained in more detail later, is programmed to effect the necessary operations on the digital signals with the view to carrying out the necessary adaptation of the signals, and to adjust the hearing aid for the relevant user.
• DSP digital signal processor
• the output signal is then fed to a digital-analogue converter 12, from which analogue output signals are fed to a sound transducer 13, such as a miniature loudspeaker.
• a digital-analogue converter 12 from which analogue output signals are fed to a sound transducer 13, such as a miniature loudspeaker.
• the hearing aid contains a storage unit 14, which in the example shown is an EEPROM (electronically erasable programmable read-only memory).
• the digital signal processing and adapter circuit 6 which in the example shown consists of a digital signal processor (DSP), contains a central processor (CPU) 7 and a number of internal storage units 8-11 , these storage units containing data and programmes, which are presently being executed in the DSP circuit 6.
• the circuit 6 thus contains a programme- ROM (read-only memory) 8, a data-ROM 9, a programme-RAM (random access memory) 10 and a data-RAM 11.
• the two first-mentioned contain programmes and data which constitute permanent elements in the circuit, while the two last-mentioned contain programmes and data which can be changed or overwritten.
• the external EEPROM 14 is normally considerably larger, e.g. 4-8 times larger, than the internal RAM, which means that certain data and programmes can be stored in the EEPROM so that, when there is need for it, they can be read into the internal RAMs for execution, in that these special data and programmes can thus later be overwritten again by the normal operational data and working programmes.
• the external EEPROM can thus contain a series of programmes, which are used only in special cases, such as e.g. start-up programmes.
• the flow diagram in fig. 2 For an explanation of how the invention is implemented in the hearing aid, reference is made to the flow diagram in fig. 2.
• a regular, built-in switch e.g. a pushbutton
• the inherent delay period 36 shown uppermost on the right-hand side is started, this period extending from the top and downwards along the symbolic time axis.
• a start code from the external EEPROM 14, cf. block 30 in fig. 2 is transferred to the programme-RAM block 10 in fig. 1.
• This start code gives rise to the transfer, cf. block 31 in fig. 2, of an operating system from EEPROM 14 to the DSP circuit 6 in fig. 1 , after which, cf. block 32 in fig. 2, the programme application and its associated data etc. are transferred by the operating system from EEPROM 14 in fig. 1 , so that the DSP circuit 6 is now completely operative and has been supplied with the necessary programmes, data etc., to customise the hearing aid for the individual user. Accordingly, the hearing aid is fully operative and, if it is not placed in position in the user's ear canal, it will oscillate due to the coupling between the transducer 13 and the microphones 2.
• the timer sequence starts and a count is effected from that number of seconds for which the aid's comfort delay period is set and down to 0, which is indicated in fig. 2 by the logical steps 33, 38.
• the hearing aid is returned to normal, cf. block 39, in that the above-mentioned blocking is cancelled.
• the timer is also used to control a block 34, see fig. 2, which generates a short acoustic signal ("beep") with a suitable frequency, cf. the logical step 35, in that the aid is programmed with that number of timer steps there must be between each beep.
• the hearing aid in fig. 1 is programmed to implement the comfort delay period 37 in extension of the hearing aid's start-up period 36, and an acoustic signal 34 which notifies the user that the hearing aid is switched on and that it is operative, but that the comfort delay period has not yet expired.
• the signal path from the microphone 2 to the transducer 13 is not desired to be blocked completely, but it is desired instead to reduce the hearing aid's amplification by a number of dB, e.g. 40-50 dB, this can also be effected in a programmable manner and independently of the sound level of the special acoustic signals controlled by block 34.
• the comfort delay period can be controlled by a commonly-known time constant circuit, a digital counter or RC circuits. If the hearing aid involved is an analogue aid, in practice use will often be made of a small digital circuit with a timer for controlling and setting the comfort delay period.

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• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Neurosurgery (AREA)
• Otolaryngology (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Telephone Function (AREA)
• Circuit For Audible Band Transducer (AREA)

Applications Claiming Priority (4)

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• 2001
  • 2001-08-10 AU AU2001279602A patent/AU2001279602A1/en not_active Abandoned
  • 2001-08-10 WO PCT/DK2001/000533 patent/WO2002013576A1/en active IP Right Grant
  • 2001-08-10 EP EP01957779A patent/EP1310138B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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