1. in a manner relating to or produced by sound waves with frequencies below the range of human hearing (below approximately 20 Hz)
Usage: technical; physics/acoustics

Examples

• The elephant communicated infrasonically across the savanna.
• Whales produce infrasonically generated calls that travel vast distances underwater.
• The device vibrates infrasonically, below the threshold of human perception.
• Seismic waves can propagate infrasonically through the Earth's crust.
• The speaker was designed to emit frequencies infrasonically for specialized research.