Abstract: Objective    To investigate the characteristics and clinical values of sound pressure level (SPL) of snoring sounds in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and simple snoring (SS).　Methods    45 patients with OSAHS and 20 patients with SS underwent polysomnography and simultaneously snoring SPL recording. Equivalent continuous sound level A (LAeq), peak level (Lpeak) and cumulative percent level (L10, L50 and L90) of the 7 hour-snoring were subtracted, and the correlations with AHI, BMI and age were analyzed.　Results    The differences of LAeq and L10 between snoring sounds of SS and OSAHS were statistically significant. Positive correlation was found between AHI and LAeq, Lpeak, L10 with the coefficients of 0.676， 0.457 and 0.653 respectively. BMI was positively correlated to LAeq and L10 with the coefficients of 0.341 and 0.379 respectively. Age was negatively correlated to LAeq and the coefficient was -0.279.　Conclusion    1. The SPL parameters of overnight snoring sounds are affected by AHI, BMI and age of patients, among which the effect of AHI is the greatest. LAeq and L10 of the snoring sounds have the strongest correlation to AHI. 2. LAeq and L10 are important acoustic characteristics of snoring sounds. It appears that they may have clinic value on roughly distinguish OSAHS from SS and evaluate the severity of OSAHS.

Key words: Simple snoring, Equivalent continuous sound level A, Cumulative percent sound leve, Obstructive sleep apnea-hypopnea syndrome, Snoring sounds