(Credit: CREATISTA/Shutterstock) When someone says "suspense is in the air," they're being more literal than they realize. A new study from German researchers shows that we exhale a unique mix of chemicals when experiencing certain strong emotions, such as fear or excitement, and that these invisible signatures can be monitored to track how an individual or crowd of people is responding. To test their theory, they went to the theater, where suspense, terror and laughter abound. That our bodies emit different chemicals depending on our physiology was known — it's how a Breathalyzer works, for example — but it had never been well-studied in the context of emotions. Strong emotions, such as fear, produce aromatic signatures revealed by chemicals seeping through our sweat glands — it's what gave rise to the notion of "smelling fear." Getting a glimpse at the full range of emotions as documented by our exhalations hadn't been successfully tested, however.