So, I did a little research and found an article from the
journal Science in 2003. A study from the University of CA at
San Francisco (UCSF) actually looked at baby rats who listened
to white noise for prolonged periods of time. The researchers
found that the part of the auditory cortex (in rats) that is
responsible for hearing, did not develop properly after
listening to the white noise. Interestingly, when the white
noise was taken away, the brain resumed normal development.
Again, this study was in baby rats, and to my knowledge has not
been duplicated. But, these baby rats were exposed to hours on
end of "white noise which may not be the same thing as sleeping
with a sound machine at night. We might need to be more
concerned about background white noise. We do know that babies
learn language by listening and absorbing human speech. They
need to hear their parent's talking to them from the time they
are born. They listen to not only their parent's speech, but
also to siblings, grandparents etc. and from an