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US 5,687,241 AGranted
Circuit arrangement for automatic gain control of hearing aids
AssigneeTopholm & Westermann ApS
InventorCarl Ludvigsen
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AssigneeTopholm & Westermann ApS
InventorCarl Ludvigsen
Estimating the term…
A circuit arrangement for a preferably programmable hearing aid with at least one microphone, at least one electronic signal processing circuit (3), with at least one channel and one output transducer (7), in which the electronic signal processing circuit (3) contains a control circuit for continuous determination or calculation of a percentile value or several percentile values of the input signal from a continuous analysis and evaluation of the frequency and/or amplitude distribution of the input signal, whereby these percentile values serve either directly or indirectly as control signals for controlling the gain and/or frequency response of the electronic signal processing circuit, whereby these percentile values serve directly or indirectly as control signals for closed-loop control of the gain and/or frequency response of the electronic signal processing circuit, whereby at least one percentile estimator (10) is connected on the input side, the percentile estimator consisting of an integrator (11 ) and a first control stage (12) for up-counting connected with the integrator and a second control stage (13) for down-counting connected with the integrator and of a comparator stage (14) with at least two inputs, whereby the input of the circuit is connected directly or indirectly with one input of the comparator stage (14), a second input of the comparator stage being connected with the output of the integrator (11 ) and directly or indirectly with the signal processing circuit (3) via a combination and control logic (15) and via at least one control line, the two outputs of the comparator stage (14) being connected with the control stage (12) or control stage (13).
A circuit arrangement for a preferably programmable hearing aid with at least one microphone, at least one electronic signal processing circuit (3) and one output transducer (7), in which the electronic signal processing circuit (3) has a transfer characteristic controllable in response to control signals and contains a control circuit for continuous determination of at least one percentile value of the input signal from a continuous analysis and evaluation of the input signal, whereby said percentile values serve either directly or indirectly as said control signals.
A hearing aid having a microphone for providing an input signal representing sound, a processor for said input signal in accordance with a transfer characteristic determined at least in part by a processor control signal, and an output transducer producing sound in accordance with the processed signal, said hearing aid further comprising a control circuit receiving said input signal and comparing said input signal to a reference signal derived from a recent history of said input signal, said control circuit including means for controlling said reference level such that a desired percentage of input signals are above said reference level, said reference level being supplied to said processor as said processor control signal.
Dependencies are inferred from the claim text.