목적: 23.4% of the world's population has various kinds of hearing loss. 56% of which are caused by different middle ear diseases, 30% are caused by inner ear diseases, 10% are congenital deafness, and 4% are caused by birth defects of the outer and middle ear combined. In 2018-2020, we conducted a study on hearing improvement surgery on 240 patients with chronic otitis media and hearing loss over 15 dB. 방법:240 patients who participated in the study had chronic otitis media and hearing loss with a bone-air gap of more than 15 dB. 92 patients (38.3%) had cholesteatoma, 55 patients (22.9%) had granuloma, 41 patients (17.1%) had adhesive inflammation of the middle ear. In patients with chronic otitis media and adhesion inflammation, we performed a one-step surgery to patch up the tympanic membrane and reconstruct the auditory bones with a titanium prosthesis. 결과:Tympanoplasty type 3 with the complete reconstruction of the auditory bone chain (Tympanoplasty III Typ-PORP) surgery was performed on 148 patients (61.6%) with a 2.5 mm titanium prosthesis, and in 129 patients (87.1%) the bone-air gap decreased down to 5-10 dB. Also, tympanoplasty type 3 with the complete reconstruction of the auditory bone chain (Tympanoplasty III Typ-PORP) surgery with titanium prosthesis to reconstruct the auditory bone chain was performed on 42 patients (17.5%) that had complete destruction of auditory bones with loss of ability to transmit sound and 35 patients (83.3%) had a decrease in bone-air gap down to 10 dB and had a hearing improvement. Apart from that, we performed Tympanoplasty III Typ surgery using the cartilage and perichondrium with Canal wall down, Canal wall up techniques on 50 patients (20.8%). 결론:In 87.1% of the 148 patients that underwent auditory bone chain replacement using PORP had a hearing improvement of 10-25 dB. Also, 83.3% of the 42 patients (17.5%) that underwent auditory bone chain replacement using TORP had a hearing improvement of 10-20 dB.