Table 2.

Sound levels directly before and during sleep-protected time and correlations between sound levels and sleep duration during sleep-protected time in the study group.

Sound measurement	Sound level		Correlation
	Before sleep-protected time, Me (IQR), (dB)	During sleep-protected time, Me (IQR), (dB)	Correlation coefficient (Spearman rank)	P
LAeq20sec	46 (44–51)	47 (45–50)	− 0.41	0.02
LAmin	43 (40–45)	43 (40–45)	− 0.38	0.04
LAmax	59 (56–61)	58 (55–60)	− 0.64	0.0001

IQR—Interquartile Range, LAeq20sec—A-weighted equivalent sound level measured over 20 s. time period, LAmax—maximum sound level in 20 s. time period, LAmin—minimum sound level in 20 s. time period, Me—median value.