did not reach statistical significancep = 0.3524
As illustrated in Figure 2A , when environmental decibel levels increased, NS-SCR frequency increased during the stages without intervention, while NS-SCR frequencies remained flat during the stages of interventions, although these differences did not reach statistical significance at 0.05 during formal testing (joint Wald-Test: χ ( 2 ) 2 = 2.09, p = 0.3524).