Abstract: Hearing disorders are the most prevalent disabling conditions reported all over the world, that affect about 10% of the population. It adversely affects physical, cognitive, behavioral, and social functions, as well as the general quality of live. The first electrical hearing instruments was introduced 100 years ago, but only about 20% of those who could benefit from hearing aids wear them, moreover, surveys suggested that about only 50% of hearing aid users are satisfied with their hearing instruments. This indicates hearing technology even today is a prominent research area. The aim of this thesis is to design a system that fits most of the popular cases of patients with hearing impairments; these patients suffering of moderate hearing loss, were the defected frequency region is around (1 KHz). Most of hearing impaired patients are fall in the region of frequencies from 500 Hz to 4 KHz; in which these cases are highly affects speech intelligibility and understanding. The designed circuit was simulated on the computer by using Electronic workbench Multisim Version 9 program to test the characteristics of the linear and non-linear amplification. The operation of the gain compression and the volume control of the circuit was tested also. The results from the simulation test show that the gain control circuit minimize the gain to 38 dB for very high input signals and maximize it to 65 dB in case of very low input signals. This will protect the patient from excessive loudness in high input levels. Also, the results show the effects of the frequency selector on the overall system gain when changing the frequency, in which the gain is maximized around the designed center frequency (1 KHz), and how the gain is minimized as we go away decreasing or increasing from the defected frequency region which give more protection to the non-defected frequency regions of the patient.