Patent ID: 8150049

Claim:
A digital hearing aid, comprising: an amplification unit for amplifying an external voice signal, input through a microphone; an Analog/Digital (AD) converter for converting an analog signal, amplified by the amplification unit, into a digital signal; at least one signal processing unit for performing gain fitting and digital signal processing on the digital signal output from the AD converter; a Digital/Analog (DA) converter for converting the digital signal, processed by the signal processing unit, into an analog signal; a receiver driver for outputting the analog signal, output from the DA converter, through a receiver; and a gain obtainment unit for performing gain fitting by utilizing both resonance gains, obtained by an external ear canal modeling circuit implemented according to shape characteristics of structures of external ear canals, and gains, obtained through a hearing test, as gain factors for the signal processing unit wherein the gain obtainment unit comprises: the external ear canal modeling circuit for modeling the structures of the external ear canals using an LC filter, thus extracting frequency characteristics; an envelope detector for outputting a DC voltage corresponding to frequency characteristics output from the external ear canal modeling circuit; a successive approximation AD converter for modulating the DC voltage, output from the envelope detector, into a digital signal; at least one comparator for generating a control signal required to extract a maximum gain factor at a frequency at which a maximum gain level is obtained, and a gain factor at a specific frequency, from each of an output of the successive approximation AD converter and an output of the hearing test; and an adder for adding a maximum gain factor, output from the successive approximation analog/digital converter, to a maximum gain factor, obtained through the hearing test, in response to the control signal output through the comparator, and outputting a resulting gain factor to the signal processing units.