Infrasound refers to sound waves with frequencies below the normal range of human hearing, which is typically 20 Hz to 20 kHz. Synonyms for infrasonics include low-frequency sound, subsonics, and bass tones, which can often be felt more than they are heard. Infrasonic waves can be generated by natural phenomena such as earthquakes and weather patterns, as well as human-made sources like machinery and aircraft. These waves can have both positive and negative effects on human health, including inducing feelings of fear or unease, causing headaches, and even altering heart rate and blood pressure. Understanding infrasonics and their effects is essential in many fields, including engineering, medicine, and environmental science.