That Haunted Feeling May Be Caused by a Sound You Can’t Hear

Researchers found that inaudible infrasound can still affect the body and mood.

In a study of 36 participants, exposure to 18 Hz infrasound during music listening raised salivary cortisol and irritability.

People exposed to infrasound also reported slightly more negative emotions, even though they could not tell when it was present.

The findings suggest low-frequency sound may trigger stress responses in everyday environments without being consciously heard.