Several days ago, I ran across an article somewhere that referred to research done a few years ago on mice. In exploring the impact of various types of sounds on the brains of mice, an unexpected discovery was made, i.e., that cells in the hippocampus region of the mice subjected to silence regenerated. This area of the brain is where memory, emotions, and learning may take place. This was discussed in Huffington Post in an article by Carolyn Gregoire .(http://www.huffingtonpost.com/entry/silence-brain-benefits_us_56d83967e4b0000de4037004)
The original research was done by Imke Kirste, Zeina Nicola, Gola Kronenberg, and Gerd Kempermann and may be found here. https://www.researchgate.net/publication/259110014_Is_silence_golden_Effects_of_auditory_stimuli_and_their_absence_on_adult_hippocampal_neurogenesis
It was suggested that this may finding may result in some therapies for various illnesses including Alzheimers and depression. I think it is also a reminder to us of the fact that our bodies really do benefit from silence at times. I've often thought that our brains are probably changing - moving away from what might be a natural tendency for humans to reflect and think deeply. When we are constantly interrupted by noise of any sort, it makes it difficult to maintain a train of thought and think long enough and deeply enough to reach more than just cursory conclusions. I would love to see some research done that explored differences in quality and depth of thought under conditions of silence and noise.