"Statistically insignificant" isn't a loose term you can throw around just because the sample size is small.
Here's the actual study, FYI: http://journal.frontiersin.org/article/10.3389/fnhum.2017.00...
Here's the actual study, FYI: http://journal.frontiersin.org/article/10.3389/fnhum.2017.00...
I tend to agree with this study, because of my personal experience with sound and its affect on my sleep, but I don't think this is anything but a reason to do a more in-depth study.
(honest question, not trying to sound snarky or anything.)