Babies can sleep in a variety of light and noise conditions. But it can help to keep noise and light levels consistent while baby is in bed.

Try dimming the lights as you get your baby ready for bed. In the daytime, closing blinds or curtains will help.
By darkening the room, you reduce the amount of stimulation around your baby, which will help calm and settle your child. A darkened room also tells baby that it’s time for rest.
Once your baby is in bed, baby will sleep better if the amount of light in the room is consistent.
Children can sleep with some noise. Your child doesn’t need an absolutely silent room to sleep. But it is easier for baby to go to sleep when noise levels are kept consistent. If baby falls asleep to noise, hearing less noise might wake baby up.
DiLeo H.A., Reiter, R.J. & Taliaferro, D.H. (2002). Chronobiology, melatonin, and sleep in infants and children. Pediatric Nursing, 28, 35-39.
Peirano, P., Algarin, C. & Uauy, R. (2003). Sleep-wake states and their regulatory mechanisms throughout early development. The Journal of Pediatrics, 143, 870-879.