Diagnostic accuracy evaluation of nasal sound spectral analysis compared with peak nasal inspiratory flow in nasal septal deviation

Background: Noninvasive evaluation of nasal airflow has remained a constant challenge for clinicians. A recently developed method for measurement of nasal obstruction has been evaluated. This study was designed to compare results of nasal sound spectral analysis (NSSA) with results of peak nasal inspiratory flow (PNIF) and visual analog scale (VAS) of nasal obstruction. Main outcome measure was diagnostic accuracy evaluation of NSSA compared with PNIF in nasal septal deviation. Methods: Analysis of original nasal sounds was performed using the ameliorated NSSA system with a software program and evaluation of nasal inspiratory sound and its intensity into spectral and frequency scale was performed using fast Fourier transform. NSSA and PNIF were performed on 43 patients with nasal septal deviations and 40 healthy subjects. We characterized the following frequency spectrum using a series of variables: low frequency (0-1 kHz), medium frequency (1-2 kHz), and high frequency (2-4 kHz). Results: A significant difference was observed between PNIF values and nasal inspiratory sound intensity of the deviated patients and the control group (p < 0.001). A correlation was observed in patients between NSSA results at a frequency range of 2-4 kHz and PNIF results. A cutoff between normal and pathological of 15.2 ± 2.0 dB (2-4 kHz) for NSSA and 118.0 ± 15.5 L/min for PNIF was calculated. No significant differences in terms of sensitivity of NSSA and PNIF (86.04% versus 79.07%) and specificity (82.50% versus 77.50%) were computed. Conclusion: NSSA and PNIF provide valuable information to aid in support of clinical decision making.