We investigated the effects of lateral osteotomy on nasal sound intensity levels in 34 patients who underwent rhinoplasty. Four groups were evaluated: group 1, preoperative rhinoplasty with lateral osteotomy (Preop-RPwithLO); group 2, postoperative rhinoplasty with lateral osteotomy (Postop-RPwithLO); group 3, preoperative rhinoplasty without lateral osteotomy (Preop-RPwithoutLO); and group 4, postoperative rhinoplasty without lateral osteotomy (Postop-RPwithoutLO). By sound analysis, low-frequency (Lf; 500-1000 Hz), medium-frequency (Mf; 1-2 kHz), and high-frequency (Hf; 2-4 and 4-6 kHz) nasal sound intensities were defined. Mf-left values of Postop-RPwithLO were significantly lower than those of Preop-RPwithLO, and Mf-left values of Postop-RPwithoutLO were significantly higher than those of Postop-RPwithLO and Preop-RPwithoutLO. Hf-right values of Preop-RPwithoutLO were significantly higher than those of Postop-RPwithLO and Postop-RPwithoutLO. Hf-total values of Postop-RPwithoutLO were significantly lower than those of Preop-RPwithoutLO. Nasal airway width decreased and nasal sounds, especially Mf sound intensities, increased in the nonlateral osteotomy group (group 4). When lateral osteotomy is performed, the nasal air passage may be adjusted as required by the surgeon, the air passage in the nasal valve region may not be narrowed, and nasal sound intensities may decrease. During postoperative follow-ups, increased Mf and Lf nasal sound intensities should be considered for the narrowness of the nasal passage and lower patency of the nasal cavities. Nasal sound analysis is a noninvasive technique and can also be used to evaluate nasal patency in septoplasty and rhinoplasty patients and children and for cases in which official reports are needed in addition to acoustic rhinometry measurements.