The purpose of this study was to suggest one method of producing hearing aid gain for Korean (HAG-K) formula utilizing loudness growth of normal hearing (NH) and sensorineural hearing loss (SNHL), and long-term average speech spectrum (LTASS) for average conversational speech level. To yield HAG-K, the LTASS of NH was firstly obtained and simple equations were derived from differential dynamic ranges of SNHL which is different from those of NH according to loudness categories based on LTASS of normal hearing (LTASSNH). Then LTASS of SNHL (LTASSSN) was calculated using derived simple equations. Finally HAG-K was determined by the difference between LTASSNH and proportionally derived LTASSSN within the dynamic range of SNHL at each frequency. However, in order to calculate effective HAG-K, it is necessary to further analyze with real-ear to coupler difference by age, shape of hearing aid, upward spread of masking, occlusion effect, tonal quality and etc. Additionally, appling Korean speech intelligibility index which is different from English and evaluating user's satisfaction through self assessments should be considered. Calculating more effective HAG-K for the hearing impaired can increase degree of satisfaction after wearing hearing aids and can positively affect improving the tonal quality and reducing the period of auditory rehabilitation.