I have only worked night shift and have done this for the last three years. I have definitely noticed the closer it gets to the shift change the louder it seems to get. I think it is just so much quieter on nice that when doctors, more staff and family start showing up the volume is bound to increase. Some hospitals have put what they call " yacker trackers" in the hall which will actually signal the level of noise in the halls and works kind of like a stop light. Green= level is good, yellow= level is increasing and staff needs to be aware and red= everyone needs to decrease their level of volume. I think this is a great way to keep everyone aware of their decibel level.