Here's a study published in December of 2007 and was undertaken in Brazil. The findings suggest periodic monitoring of environments be established to accurately determine levels and implement a control strategy. I suggest "Real Time monitoring 24 hrs a day, 7 days a week, 365 days a year via "SONICU" is optimal. Here's the concluding paragraph from the study.
....Considering
the sound pressure high levels found in the study and their deleterious
effects on newborns and the health team, the results point out the need
to include interventions targeting the routine of equipment maintenance
and the attitude of relatives and professionals through continuing
educational programs. Monitoring of sound pressure levels should be
done periodically, in the morning, in the afternoon and at night and on
different days of the week.
>>> LINK <<<
