Nobody knows what causes Sudden Infant Death Syndrome. There are a many factors linked by correlation and lots of things that, again, correlate to a reduced risk. But the actual cause (or causes) have been elusive. Fascinatingly, research from Seattle Children's Hospital suggests that inner ear dysfunction and hearing impairment might play a role in some SIDS deaths. Sleeping mice with inner ear problems have a harder time waking themselves when they're positioned in a way that makes it hard to breathe. Meanwhile, a surprising number of SIDS victims were diagnosed with hearing problems.