in the illustrated device , a microphone 1 is provided as the input transducer , said microphone 1 being connected to a pre - amplifier 2 which , as indicated by 2 &# 39 ; exhibits a low - pass frequency response . the signal amplified in that manner is then divided at a point 3 and supplied to a plurality of time - discrete frequency filters 4a through 4n , i . e ., a total of n time - discrete frequency filters . of these , that referenced with 4a is a band pass which transmits frequencies from 50 hz through 600 hz . the filter 4b likewise connected at the point 3 is a band pass which is effective at frequencies from 0 . 6 khz to 2 . 5 khz . given a reduced frequency scope of the filters 4a and 4b , even more filters can be provided , as indicated by means of points 4c . finally , the filter 4n follows as the last , said filter being effective at 2 . 5 khz through approximately 8 khz given the frequency distribution specified for 4a and 4b . variable amplifiers 5a through 5n then follow the filters , said variable amplifiers 5a through 5n , together with the controlling means 6a through 6n realizing a gain control in a fundamentally known manner . the disposition of further variable - gain amplifiers is again indicated here with 5c and that of controlling means is indicated with 6c . accordingly , the signals proceed to variable amplifiers 7a through 7n which , controlled by the output voltage of the volume control 8 , undertake the volume setting . subsequently , the signals are subjected to a peak value limitation in the non - linear elements 9a through 9n in a known manner . signal distortions thereby caused are reduced by post - filtration with filters 10a through 10n which , for example , can correspond to the filters 4a through 4n in their frequency response . a possibility of augmentation by means of further channels is likewise indicated with 7c , 9c and 10c , given the variable - gain amplifiers 7a through 7n , the limiters 9a through 9n and the distortion - reducing filters 10a through 10n . the signals treated in such manner are finally additively recombined at a point 11 and are supplied via a final amplifier 12 to an earphone 13 as the output transducer . the setting of the filters 4a through 4n , controlling means 6a through 6n , and peak value limiters 9a through 9n is carried out by means of a programming circuit 14 . the filters 4a through 4n receive their control signals over the lines 15a through 15n ; the analogous case applies for the controlling means 6a through 6n over the lines 16a through 16n , over the lines 17a through 17n for the limiters 9a through 9n , and , finally , over the lines 18a through 18n for the filters 10a through 10n . for its part , the programming circuit 14 receives the setting data from an external device ( for example from an audiometer ) over one or more data lines 19 , whereby the transmission and the storage in the programming circuit 14 is controlled over a plurality of control lines 20 proceeding from the external device . the connection to the latter is provided by means of a plug - type connection 21 . when the programming circuit 14 is realized by means of a microcomputer circuit , then it can entirely or partially calculate the setting parameters itself as a function of the momentarily existing input signal which is supplied to it for this purpose over the line 22 . the manner of functioning of the device is such that the electrical signal generated in the input signal transducer , i . e . in the microphone 1 or , respectively , in an induction pick - up coil for electromagnetic oscillations replacing it , is boosted in the amplifier 2 to such a voltage level that it is easily accessible to the following signal processing . the low - pass frequency response 2 &# 39 ; obtained in the amplifier 2 prevents signal components and , under certain conditions , in - coupled noise signals which lie above half the sampling frequency from being folded - over back into the audible frequency range , given the sampling operation to be carried out in the time - discrete filters 4a through 4n . subsequently , the signal is sampled in the filters 4a through 4n and is respectively suppressed frequency - selective to such a degree that the respective parts of the signal belonging to the specified frequency ranges can be separately treated . thus , a gain control dependent on the input or output level is achieved in the variable - gain amplifiers 5a through 5n which are controlled over the controlling means 6a through 6n , whereby different , known control principles can be applied , for example , the standard agc circuits employing the short - term mean value of said levels but also the momentary value compressors as are specified by keidel and spreng in the german as no . 15 12 720 . as a result , a high degree of compensation of for dynamic auditory disruptions ( for example loudness recruitment ) is made possible . by means of the control 8 and the variable - gain amplifiers 7a through 7n driven by said control 8 , the hearing aid wearer has the possibility of bringing the volume of the output signal into a volume range which he finds comfortable . a desired non - linear signal deformation can fundamentally be achieved with the non - linear circuits 9a through 9n . in the normal case , a peak value limitation is undertaken in a known manner and , thus , the occurrence of unpleasant or even hearing - jeopardizing peak values of the output acoustic pressure level is prevented . the distortion components caused by these non - linearities are reduced in the filters 10a through 10n ; but the useful signals are left uninfluenced to the largest degree possible . the filters 10a through 10n can be eliminated when the noise - component suppression by the low - pass properties of the final amplifier 12 and the ear piece 13 is sufficient . after the combination of the sub - signals at the addition point 11 , the further treatment of the sub - signal ensues in the standard manner , i . e . it is brought to the intensity necessary for the operation of the output transducer , i . e . of the earphone 13 in the present case , in the amplifier 12 . a signal then appears at the earphone 13 which is suitable for the compensation of the respectively existing hearing impairment . given a hearing impairment wherein , for example , it is primarily the hearing ability for high frequencies which is vitiated and wherein , moreover , auditory recruitment essentially only occurs in this range , the ( unregulated ) base amplification of the frequency channels at the amplifiers 5a through 5n is to be respectively set in a known manner and in such manner that the pathological auditory threshold curve of the patient is compensated overall in the best possible manner on average . the controlling means 6a through 6n are now to be set in such manner that the dynamic loss in the respective frequency band is compensated as well as possible , i . e ., given high levels , the controlling means 6n will effect the noticeable gain reduction in the highest frequency channel , whereas the controlling means 6a remains practically without influence in the low - pass channel . the limiters 9a through 9n , finally , are to be set in a known manner such that the discomfort threshold of the patient is not noticeably transgressed by the signal level at any frequency . when the filters 10a through 10n are built in , then they are to be dimensioned in such manner that distortion components are suppressed to the highest possible degree ( for example , in that , in terms of frequency response , they are executed as duplicates of the corresponding channel separation filters 4a through 4n ). when the programming circuit 14 represents a microcomputer circuit functioning in the manner of an adaptive optimum filter , then this will only retain the above - described basic setting when , according to methods which are disclosed in the u . s . pat . no . 4 , 025 , 721 , only speech but no significant noise signal components are detected in the input signal supplied over the line 22 . when , however , spurious noise components are perceived , then , in the sense of the optimum filter function , the gain in each channel automatically is decreased all the more the greater the ratio of the noise level to the speech signal level is in the appertaining channel . the data which are supplied over the plug - type connection 21 to the programming circuit 14 can be tapped from an external device , for example an audiometer . to that end , it is necessary that the transmit part of a data interface is built into the external device , whereby the programming circuit 14 is executed in such a manner that it fulfills the function of the appertaining receive part . the data transmission from the external device to the hearing aid can ensue in accord with the signal plan of a standardized interface ( for example ccitt - v . 24 according to eia rs 232 ); it is only the signal levels which are to be matched to the operating voltage of the hearing aid . after the transmission , a declared data word or control signal initiates a non - volatile storage in an eprom or earom . a later re - programming is easily possible in that the non - volatile memory ( eprom or earom ) is erased in accord with its structure ( by means of ultraviolet radiation or electrical voltages ) and a new data set is transmitted . it will be apparent that many modifications and variations may be made without departing from the scope of the teachings and concepts of the present invention .