| One psychologist thinks that the odd sensations that people attribute to ghosts may be caused by infrasonic vibrations. |
| Seismologists and volcanologists use both seismic and infrasonic signals to monitor volcanic activity. |
| Using calls that have infrasonic fundamental frequencies, female elephants are able to communicate with large numbers of specific individuals over long distances. |
| He says he once invited people to spend a few minutes in a container he was pumping with infrasonic sound. |
| Just as seismic waves travel through Earth, infrasonic waves travel through the air. |
| Powerful infrasonic calls enable them to send messages and warnings, sometimes over long distances. |
